COMMISSION D : Electronics and Photonics (Nov. '98 - Oct. '01)

Edited by Masayuki Izutsu and Masahiro Tsuchiya



Since the fields of Electronics and Photonics include too many technological areas for us to cover every detail of their research subjects, we focus ourselves into the following representatives. Indeed, these are the subjects studied by Japanese research groups actively in the last three years, and you may be able to overview related progresses. The following reports are written by some Japanese world-leading researchers in respective research areas.

D1 Vertical Cavity Surface Emitting Lasers
K. Iga JSPS / Kogakuin University
D2 Optical Devices for Optical Fiber Networks
M. Kawachi NTT
D3 Femtosecond Technology
O. Wada FESTA / Kobe University
D4 Ultrafast Phenomena
T. Kobayashi University of Tokyo
D5 THz Technology
H. Ito Tohoku University
D6 Sensing Photonics
K. Hotate University of Tokyo
D7 Systems Photonics
T. Korokawa Tokyo University of Agriculture and Technology
H. Sasaki Oki Electric
D8 Microwave Photonics
M. Tsuchiya University of Tokyo
References D1 - D8

D1.Vertical Cavity Surface Emitting Lasers

Extensive studies and realization trials have been made on high performance vertical cavity surface emitting laser (VCSEL), which was invented by the author in 1977 at Tokyo Institute of Technology. It is a semiconductor laser which can be monolithically fabricated and considered as a promising candidate for Gigabit Ethernet, high speed LANs, computer links, optical interconnects, and so on. What have been achieved by the author's group regarding the technical progress of devices range from infrared to ultraviolet wavelengths. The expansion of operating spectra was made by developing advanced materials and fabrication technologies. For instance, a GaInNAs VCSEL device was demonstrated by the author's group, which can be formed on a GaAs substrate and can emit 1300nm band laser light. It has contributed to the wavelength coverage extension of VCSEL to longer wavelength regions. Also, a polarization controlled VCSEL was realized by using (311)B substrates. This is another development made by the author's group. It was found that this device is almost insensitive to temperature variation, which is highly advantageous for network applications of diode lasers. In conjunction with those VCSEL related technical progresses, a new technology for optical communication components has been proposed by the author's group, which is based on a planar microlens array. The device was also invented by the author and has been shown to be a promising candidate for effective packaging technology.
Related references are listed in Reference D1.
(Kenichi Iga)

D2.Optical Devices for Optical Fiber Networks

NTT Network Innovation Laboratories is one of the major Japanese research centers for optical device studies for their uses in optical fiber networks. It is affiliated with the NTT Science and Core Technology Laboratory Group, one of NTTs three laboratory groups. The mission of NTT Network Innovation Laboratories, with a five-year and a ten-year outlook, focuses on the followings:
1. Creating innovative services as well as the network concepts that will support these services.
2. Providing the new network core technologies required to win out in business competition.
3. Being a leading force in the field of innovative, core technologies.
Their details are available in the references listed in Reference D2.
(Masao Kawachi)

D3. Femtosecond Technology

In 1995, a technological consortium named FemtoSecond Technology Association (FESTA) was established in the Tsukuba area and also in the related company laboratories, where world-leading research and development activities for ultrafast all-optical devices have been performed intensively for the application to future ultrahigh throughput optical telecommunication systems. In addition, fiber-optic transmission of femtosecond laser pulses, photonic microstructures, and X-ray femtosecond techniques have been investigated in the FESTA Laboratories. The FESTA Laboratories have been operated under a governmental MITI (Ministry of International Trades and Industries) project on Femtosecond Technology, where the authors group has focused ourselves into the all-optical device researches. There, world-leading development attempts have been made for advanced all-optical switching devices, and several interesting results have been obtained up to date. They include (a) implementation of femtosecond all-optical switches using intersubband transitions in Sb-based and GaN-based QWs, (b) a 1 Tb/s all-optical demultiplexing demonstration with Sb-based prototype devices utilized, (c) picosecond-response optical amplifiers with quantum dot laser amplifier structures, which also can act as wavelength converters based on the four-wave mixing phenomenon, and (d) sub 100 fs all optical switches with organic thin film (squarylium dye) together with the demonstration of serial to parallel signal conversion to 1 Tb/s bit rate signals.
In 2001, the author moved to the Kobe University and started related works on III-V semiconductor materials and their optoelectronic device applications. In our laboratory at Kobe, we focus on, for example, investigation on formation mechanism of quantum dots in molecular beam epitaxy (MBE) growth and limit of response speed in quantum dot devices.
Related references are listed in Reference D3.
(Osamu Wada)

D4.Ultrafast Phenomena

Development of ultrashort pulse lasers
In the last 30 years, the generation of extremely short optical pulses has always been recognized as one of the most vital frontiers of science. Generation of shortest 4.7-fs visible pulses by noncollinear optical parametric amplifier (NOPA) was demonstrated by the authors group: World shortest pulses in the visible wavelength range was obtained by two sets of carefully designed chirped mirrors and a prism pair. Sub-5-fs real-time spectroscopy systems have been constructed on the basis of this pulse source.
i) Solitons in polyacetlenes:
Time dependent frequencies of carbon-carbon stretching modes were for the first time measured by using the sub-5-fs pulses. This phenomenon is explained by the formation of breather, the bound state of the charged soliton pair, which had been theoretically predicted but has not been found.
ii) Novel vibrational dynamic behaviers in molecules:
Excitation-induced modulation of vibrational frequency and amplitude in dye molecules was studied by using the sub-5-fs pulses. The frequency and amplitude modulations of the ring-breathing mode of cresyl violet doped in poly (vinyl alcohol) film were clearly observed, indicating that the mode is coupled to another vibrational mode. The mode coupling represents the Duschinsky effect.
iii) Dye molecules:
Dynamics of C--N stretching mode and N=N stretching mode of azobenzene dimethyl sulfoxide solution was investigated by using the sub-5-fs pulses. The vibrational spectra during the photo-isomerization reaction was observed successfully for the first time.
iv) Dynamic intensity borrowing in J-aggregates:
Sub-5-fs spectroscopy of phorphyrin J-aggregates has lead to a new discovery, which reveals a coherent molecular vibration coupled to the Frenkel exciton. The bleaching and induced absorption signals show synchronous oscillations with the frequency of 244-cm-1. The coherent oscillation is explained by a modulated transition dipole moment, which is due to dynamic intensity borrowing from an intense B-transition to a weak Q-transition through the ruffling mode with the 244-cm-1 frequency.
v) Quasi-one-dimensional halogen-bridged mixed-valence metal complex:
Ultrafast optical response has been extensively studied in Pt(en)2 Pt(en)_2 I2 ClO4 4 with the sub-5-fs time-resolution. The followings are new findings. Wave packet motions both in ground and self-trapped exciton (STE) states are observed as oscillatory modulations in the time-resolved reflectivity. The wave packet motion on the STE potential surface begins after about 50-fs with respect to the photoexcitaion. This delay is attributed to the lattice relaxation from the free exciton state to the STE state.
Development of new measurement system
i) Multiplex method for nonlinear susceptibility spectrum measurement:
Continuous spectrum of nonlinear susceptibility can be measured by a single shot in this system. Convolution term and chirp effect were calculated and quantified.
ii) Mid-infrared time-resolved spectroscopy apparatus:
Ultrashort pulse laser in mid IR was constructed by optical parametric amplifier. The spectrum region was 5um - 10um. Dynamics of Carbon-Carbon stretching mode in excited state of polydiacetylenes was investigated by using the system.
iii) Scanning near-field optical microscope(SNOM):
In order to observe an optical nonlinearity property of a single J-aggregate, a SNOM has been constructed. Both fluorescent and absorption spectra are successfully observed with a special resolution higher than 100 nm at room temperature and liquid helium temperature.
Quantum optics and teleportation
i) Frequency-resolved optical gating (FROG):
Second-harmonic-generation FROG (SHG FROG) and cross-correlation FROG (XFROG) have been used as a characterization method of pulses propagating through an optical medium. Time variations of intensity and phase of ultrashort pulses transmitting through a Nd+3 -doped glass plate were measured by using these techniques.
ii) Quantum teleportation and quantum information:
The goal of our research is to achieve more than 0.58 fidelity which is the current limit of accuracy in quantum teleportation. Detection system of quantum noise and optical parametric oscillator were constructed.
Related references are listed in Reference D4.
(Takayoshi Kobayashi)

D5.THz Technology

The THz-wave (very far-infrared) region has attracted significant interest in recent years. The generation of THz radiation by optical rectification or photo-conductive switching has been extensively studied by using femto-second laser pulses. Applied research, such as time domain spectroscopy (TDS), makes use of the high time resolution of THz-waves and ultra broad bandwidth up to the THz region. In contrast, our research focuses on the development of tunable THz-wave sources with high temporal and spatial coherence. Specifically, widely tunable coherent sources have a wide range of applications, such as in material science, solid state physics, molecular analysis, atmospheric research, bioscience, chemistry, gas tracing, material testing, food inspection, etc. Tunable sources already exist in the sub-THz (several hundreds GHz) frequency region, such as a backward-wave-oscillator (BWO). However, a widely tunable THz-wave source has long been desired in the frequency region above 1 THz, where the tuning capability of a BWO rapidly decreases. Several candidate schemes have been reported, although they do not avoid one or more of the following problems: large size, operational difficulty, liquid He requirement, and low output power. A compact user-friendly source will inevitably find many applications in laboratory-based research, or even commercially.
Several decades ago, it was pointed out that far-infrared or THz-wave generation could be realized by using the lattice vibrations in semiconductors. We have researched a THz-wave parametric oscillator (TPO) and THz-wave parametric generator (TPG) based on the polariton mode scattering of LiNbO3 or MgO:LiNbO3 crystals. The TPO has proved to be a useful coherent THz-wave source that operates at room temperature. It is continuously tunable in the 100- to 300-mm (1- to 3-THz) range in one operation and can emit peak powers of up to several tenths of a milli-Watt. The difference between a TPO and a TPG is that the former has an idler cavity while the latter does not. The THz-wave linewidth of a conventional TPG exceeds 500 GHz and the THz-wave output is much smaller than that from a TPO. Therefore, we concentrated our efforts on the development of a TPO system, although its linewidth was several tens of GHz.
The TPG spectrum was narrowed to the Fourier transform limit of the pulsewidth by introducing an injection seeding to the idler. The purity of the THz-wave frequency was dramatically improved to Dn/n < 10-4. Simultaneously, the output obtained was several hundred times higher than that of a conventional TPG. In addition, wide tunability and fine resolution were demonstrated using a tunable seeder. As far as we know, injection seeding to ns optical parametric generators (OPG) has not been reported until recently, due to the limit of parametric gain.
Related references are listed in Reference D5.
(Hiromasa Ito)

D6.Sensing Photonics

Fiber optic distributed sensing techniques have been extensively studied, which have provided schemes to measure, for example, distribution of longitudinal strain or lateral force along an optical fiber. In these systems, the fiber can act as a nerve network to sense damages of materials or structures in which the fiber is embedded. These techniques are the key to realize smart materials and smart structures for improving reliability, safety and security of the society. Some representatives are described in the followings.
A novel technique for fiber-optic strain-distribution sensing has been proposed and studied based on the Brillouin scattering in a fiber. A down-shifted frequency of the Brillouin scattering is changed in proportion to the applied longitudinal strain. The pump and prove lightwaves, propagating in the fiber in opposite directions with each other, are modulated in frequency, which realizes localized excitation of the stimulated Brillouin scattering. By this correlation-based continuous-wave technique, a spatial resolution of 1.0 cm has been demonstrated. This is 100 times higher than the inherent limitation of conventional pulsed lightwave techniques. Smart materials with enough spatial resolution have been realized with this technique. An international conference report (K. Hotate et al., Intern. Conf. on Optical Fiber Sensors, Venice, Oct. 2000) on this technique was evaluated as the best paper there in.
Interference characteristics in an interferometer can arbitrarily be synthesized by a technique, synthesis of optical coherence function, which has been invented by Japanese researchers. On the basis of this technique, the fiber optic distributed force sensing has been proposed and studied. The sensing mechanism is based on the polarization mode coupling, due to the force, in a polarization maintaining fiber. Propagation speed difference between the two polarization modes is used to resolve the force-applied position. Introducing a SSG-DBR (super-structured grating-distributed Bragg reflector) laser diode as a light source, which has quite a wide frequency-tunability, the spatial resolution has been improved to be about 2m. Additionally, a way to overcome the sensitivity instability of the polarization maintaining fiber as the lateral force sensor has successfully been developed.
Techniques for diagnosing fiber optic subscriber networks have also been studied also using synthesis of optical coherent function. We must measure the reflectivity distribution around the optical elements, which locate at the end of the network beyond a 5km length optical fiber, with cm order spatial resolution. A system with 6cm resolution for this purpose has already been developed. Such a high resolution have not been realized by other ways.
Utilizing the technique, synthesis of optical coherence function, a scheme to control the characteristics and the location of a dynamic grating in an Er-doped fiber due to its gain saturation has also been proposed, and various filter characteristics have been demonstrated. Recently, it has been found that the spatial phase of the dynamic grating can also be controlled, which realizes a filter with a notch at the center frequency of the reflection band. Basic experiment has successfully been done to verify the proposal.
Related references are listed in Reference D6.
(Kazuo Hotate)

D7.Systems Photonics

Systems photonics on optical signal processing, optical image processing, digital holography, and optical interconnections have been intensively studied in Japan. The technologies are aimed at the futuristic versatile optics-based systems using the advanced optoelectronic devices and components.
Related research activities are summarized as follows;
(1) Ultrafast Optical signal processing
(2) Optical interconnections
(3) Optical sensing
(4) Digital holography
(5) Optical functional devices
(6) Optical image processing
(7) Optical powering systems
As one of the representative research attempts, the following subject is described here in more details. Inter-chip free-space optical interconnection modules have been investigated intensively. This is aimed at solving the pin-I/O bottleneck problem at the interfaces of silicon integrated circuits. The scalability of the photonic circuit is theoretically analyzed by taking account of the minimum feature size requirement of each diffractive optical element used in the connection. The study showed that interconnection densities of 1000 to 2000 channels / cm is possibly available for a 40 mm interconnection length over a 3-mm-thick optical substrate. Diffraction-limited imaging capability has been demonstrated by using a fabricated proto-type, which have shown clearly its applicability to inter-chip free-space interconnections. Photonic circuit insertion losses of -23.4 dB for TE polarization and -25.9 dB for TM polarization as well as a polarization dependent loss of 2.5 dB are found to be primarily caused by a pair of binary linear gratings used for beam deflections. Design modifications aimed at insertion loss reduction and further improvement of the tolerance are also discussed.
Their details are described in references in Reference D7.
(Takashi Kurokawa and Hironori Sasaki)

D8.Microwave Photonics

As well known, the fiber-optic communications technologies have made tremendous progresses in the last decade. It is no doubt that the long distance communications are and will be dominated by the fiber-optic transmission techniques. As a consequence of the trend and its extension, the technologies have been brought from the standard long distance point-to-point communications through the large and small size multi-points-to-multi-points networking systems into the new area: the user access systems. On the other hand, the mobile telephone is another recent huge technological innovation of telecommunications, which has been aimed at convenience mainly for many end users. One of the biggest related topics in Japan is, indeed, the start of the third generation mobile phone service in October 2001, which was the earliest in the world. The general trends of the mobile phone developments are now focused into the broadband nature as in the case of the third generation service.
It is rather clear that these two major telecommunication technologies are getting closer: the broadband fiber-optic communications technologies have attempted to approach end users and the end-user-friendly mobile telephone services have started seeking for the broadband properties. What is expected to happen technically where those two streams meet each other? One fairly likely situation is effective merge of the two technologies. The field of Microwave Photonics stands on this idea, in which the interdisciplinary research activities have been performed. Indeed, many radio-on-fiber systems have been constructed in subway systems, large brides, submarine tunnels, and hotels in Japan. It is also notable that techniques in this interdisciplinary research field have been extended their possible application frontiers to high frequency electromagnetic field measurements and high-density wavelength division multiplexed fiber-optic communications.
The related papers of the authors group can be found in Reference D8.
(Masahiro Tsuchiya)

References

D1. Vertical Cavity Surface Emitting Lasers
Amano, T., F. Koyama, N. Furukawa, N. Nishiyama, A. Matsutani and K. Iga[2000a], Micromachined AlGaAs/GaAs vertical cavity filter with adjustable temperature dependence and wavelength trimming ability, Electron. Lett., vol. 36, no. 1, pp. 74-76

Amano, T., F. Koyama, N. Nishiyama and K. Iga[2000b], Temperature-insensitive micromachined AlGaAs-GaAs vertical cavity filter, IEEE Photon. Technol. Lett., vol. 12, no. 5, pp. 510-512

Amano, T., F. Koyama, N. Nishiyama and K. Iga[2000c], 22 multiwavelength micromachined AlGaAs/GaAs vertical cavity filter array with wavelength control layer, Jpn. J. Appl. Phys., vol. 39, no. 7A, pp. L673-L674

Aoki, Y., T. Kato, R. J. Mizuno and K. Iga[1999], Micro-optical bench for alignment-free optical coupling, Appl. Opt., vol. 38, no. 6, pp. 963-965

Aoki, Y., Y. Shimada, R. J. Mizuno and K. Iga[2000a], Two-dimensional alignment-free optical interconnect using micro optical bench scheme, Optical Review, vol. 7, no. 1, pp. 54-57

Aoki, Y., R. J. Mizuno, Y. Shimada and K. Iga[2000b], Fundamental study of parallel moduling scheme based on micro-optical bench and collimating planar microlenses, Jpn. J. Appl. Phys., vol. 39, no. 3B, pp. 1529-1532

Aoki, Y., Y. Shimada and K. Iga[2000c], Collimation characteristics of planar microlens for parallel optical interconnect, Optical Review, vol. 7, no. 6, pp. 483-485
Arai, M., N. Nishiyama, S. Shinada, F. Koyama and K. Iga[2000a], AlAs oxidation system with H2O vaporizer for oxide-confined surface emitting lasers, Jpn. J. Appl. Phys., vol. 39, no. 6A, pp. 3468-3469

Arai, M., N. Nishiyama, S. Shinada, A. Matsutani, F. Koyama, and K. Iga[2000b], Vertical-cavity surface-emitting laser array on GaAs(311)B substrate exhibiting single-transverse mode and stable-polarization operation, Jpn. J. Appl. Phys., vol. 39, no. 6B, pp. L588-L590

Arai, M., N. Nishiyama, S. Shinada, A. Matsutani, F. Koyama and K. Iga[2000c], Highly stable single polarization operation of GaInAs/GaAs vertical-cavity surface-emitting laser on GaAs (311)B substrate under high-speed modulation, Jpn. J. Appl. Phys., vol. 39, no. 8B, pp. L858-L860

Ariga, M., Y. Sekido, A. Sakai, T. Baba, A. Matsutani, F. Koyama and K. Iga [2000], Low threshold GaInAsP lasers with semiconductor/air distributed Bragg reflector fabricated by inductively coupled plasma etching, Jpn. J. Appl. Phys., vol. 39, no. 6A, pp. 3406-3409

Baba, T., K. Inoshita, H. Tanaka, J. Yonekura, M. Ariga, A. Matsutani, T. Miyamoto, F. Koyama and K. Iga[1999], Strong enhancement of light extraction efficiency in GaInAsP 2-D-arranged microcolumns, IEEE J. Lightwave Tech., vol. 17, no. 11, pp. 2113-2120

Chen, Z., D. Schlenker, T. Miyamoto, T. Kondo, M. Kawaguchi, F. Koyama and K. Iga[1999], High temperature characteristics of near 1.2m InGaAs/AlGaAs lasers, Jpn. J. Appl. Phys., vol. 38, no. 10B, pp. L1178-L1179

Hatori,N., A. Mizutani, N. Nishiyama, F. Motomura, F. Koyama and K. Iga[1999], P-type delta-doped InGaAs/GaAs quantum well vertical-cavity surface-emitting lasers, Electronics and Communications in Japan, vol. 82 Pt. 2, no. 4, pp. 54-60

Honda, T., T. Miyamoto, T. Sakaguchi, H. Kawanishi, F. Koyama and K. Iga[1998a], Effect of piezo electric field on emission characteristics GaN/AlGaN quantum wells, J. Crystal Growth, vol. 180/190, pp. 644-647

Honda, T., A. Inoue, M. Mori, T. Shirasawa, N. Mochida, K. Saotome, T. Sakaguchi, A. Ohtomo, M. Kawasaki, H. Koinuma, F. Koyama and K. Iga[1998b], GaN growth on ozonized sapphire(0001) substrates by MOVPE ,J.Crystal Growth, vol. 195, pp. 319-322

Honda, T., H. Kawanishi, T. Sakaguchi, F. Koyama and K. Iga[1999], Characteristic temperature estimation for GaN-Based lasers, MRS Internet J. Nitride Semicond. Res., vol. 4S1, G6.2

Iga K.[1999], Surface emitting lasers ,Electronics and Communications in Japan, vol. 82 Pt. 2, no. 10, pp. 70-82

Iga, K[2000], Surface emitting laser-its birth and generation of new optoelectronics field, IEEE J. Select. Top. Quantum Electron., vol. 6, no. 6, pp. 1201-1215

Irikawa, M., T. Ishikawa, Y. Sasaki, K. Iwasawa, I. Suemune and K. Iga [1998], Some effects of conduction band nonparabolicity on electron reflection spectrum of multiquantum barriers, J. Appl. Phys., vol. 84, no. 9, pp.4667-4672

Irikawa, M., T. Ishikawa, T. Fukushima, H. Shimizu, A. Kasukawa and K. Iga[2000], Improved theory for carrier leakage and diffusion in multiquantum-well semiconductor lasers, Jpn. J. Appl. Phys., vol. 39, no. 4A, pp. 1730-1737

Kageyama, T., T. Miyamoto, S. Makino, F. Koyama and K. Iga[1999], Thermal annealing of GaInNAs/GaAs quantum wells grown by chemical beam epitaxy and its effect upon photoluminescence, Jpn. J. Appl. Phys., vol. 38, no. 3B, pp. L298-L300

Kageyama, T., T. Miyamoto, S. Makino, F. Koyama and K. Iga[2000a], High-temperature operation up to 170 C of GaInNAs-GaAs quantum-well lasers grown by chemical beam epitaxy, IEEE Photon. Technol. Lett., vol. 12, no. 1,pp. 10-12

Kageyama, T., T. Miyamoto, S. Makino, F. Koyama and K Iga[2000b], Optical quality of GaNAs and GaInNAs and its dependence on RF cell condition in chemical beam epitaxy, J. Crystal Growth, vol. 209, pp. 350-354

Katayama, T., Y. Munetaka and K. Iga[1999], "Improvement of electric-field-assisted ion exchange method for planar microlens array fabrication", Jpn. J. Appl. Phys., vol. 38, no. 2A, pp. 775-776

Katayama, T., T. Takahashi and K. Iga[2000], Optical pattern recognition experiments of Walsh spatial frequency domain filtering method, Jpn. J. Appl. Phys., vol. 39, no. 3B, pp. 1576-1581

Kawaguchi, M., E. Gouardes, D. Schlenker, T. Kondo, T. Miyamoto, F. Koyama and K. Iga[2000a], Low threshold current density operation of GaInNAs/GaAs quantum well lasers grown by metalorganic chemical vapour deposition, Electron. Lett., vol. 36, no. 21, pp. 1776-1777

Kawaguchi, M., T. Miyamoto, E. Gouardes, D. Schlenker, T. Kondo, Fumio Koyama and K. Iga[2000b], Optical quality dependence on growth rate for metalorganic chemical vapor deposition grown GaInNAs/GaAs, Jpn. J. Appl.Phys., vol. 39, no. 12A, pp. L1219-L1220

Koyama, F., Dietmar Schlenker, T. Miyamoto, Zhibiao Chen, A. Matsutani, T. Sakaguchi and K. Iga[1999], 1.2m highly strained GaInAs/GaAs quantum well lasers for singlemode fibre datalink, Electron. Lett., vol. 35, no. 13, pp. 1079-1081

Koyama, F., D. Schlenker, T. Miyamoto, Z. Chen, A. Matsutani, T. Sakaguchi and K. Iga[2000a], Data transmission over single-mode fiber by using 1.2-?m uncooled GaInAs-GaAs laser for Gbit/s local area network, IEEE Photon. Technol. Lett., vol. 12, no. 2, pp. 125-127

Koyama, F., T. Amano, N. Furukawa, N. Nishiyama, M. Arai and K. Iga[2000b], Micromachined semiconductor vertical cavity for temperature insensitive surface emitting lasers and optical filters, Jpn. J. Appl. Phys., vol. 39, no. 3B, pp. 1542-1545

Makino, S., T. Miyamoto, T. Kageyama, N. Nishiyama, F. Koyama and K. Iga[2000], GaInNAs/GaAs quantum dots grown by chemical beam epitaxy, J. Crystal Growth, vol. 221, pp. 561-565

Matsutani, A., F. Koyama and K. Iga [1998], Low bias voltage dry etching of InP by inductively coupled plasma using SiCl4/Ar, Jpn. J. Appl. Phys., vol. 37, no. 12, pp. 6655-6656

Matsutani, A., H. Ohtsuki, F. Koyama and K. Iga[1999], Vertical and smooth etching of InP by Cl2/Xe inductively coupled plasma, Jpn. J. Appl. Phys., vol. 38, no. 7A, pp. 4260-4261

Matsutani, A., H. Ohtsuki, F. Koyama and K. Iga[2000a], Plasma diagnostics in inductively coupled plasma etching using Cl2/Xe, Jpn. J. Appl. Phys., vol. 39, no. 3A, pp. 1435-1436

Matsutani, A., H. Ohtsuki, F. Koyama and K. Iga[2000b] , Emission spectrochemical analysis in dry etching process of InP by Cl2- inductively coupled plasma, Jpn. J. Appl. Phys., vol. 39, no. 10, pp. 6109-6110

Miyamoto, T., S. Sato, Z. Pan, D. Schlenker, F. Koyama and K. Iga[1998], GaNAs/GaInAs short-period superlattice quantum well structures grown by MOCVD using TBAs and DMHy, J. Crystal Growth, vol. 195, pp. 421-426

Miyamoto, T., K. Takeuchi, T. Kageyama, F. Koyama and K. Iga[1999], Chemical beam epitaxy of GaInNAs/GaAs quantum wells and its optical absorption property, J. Crystal Growth, vol. 197, pp. 67-72

Miyamoto, T., T. Kageyama, S. Makino, D. Schlenker, F. Koyama and K. Iga[2000], CBE and MOCVD growth of GaInNAs, J. Crystal Growth, vol. 209, pp. 339-344

Mizuno, R.J., Y. Aoki, Y. Shimada and K. Iga[2000], A bidirectinal optical module based on stacked planar optical circuit, Jpn. J. Appl. Phys., vol. 39, no. 3B, pp. 1522-1528

Mochida, N., T. Honda, T. Shirasawa, A. Inoue, T. Sakaguchi, F. Koyama and K. Iga[1998], Crystal orientation dependence of p-type contact resistance of GaN ,J. Crystal Growth, vol. 180/190, pp. 716-719

Nishiyama, N., A. Mizutani, N. Hatori, M. Arai, F. Koyama and K. Iga [1998], Single-transverse mode and stable-polarization operation under high-speed modulation of InGaAs-GaAs vertical-cavity surface-emitting laser grown on GaAs (311) B substrate, IEEE Photon. Technol. Lett., vol. 10, no. 12, pp. 1676-1768

Nishiyama,N., A. Mizutani, N. Hatori, M. Arai, F. Koyama and K. Iga[1999a], Lasing characteristics of InGaAs-GaAs polarization controlled vertical-cavity surface-emitting laser grown on GaAs (311)B substrate, IEEE J. Select. Top. Quantum Electron., vol. 5, no. 3, pp. 530-536

Nishiyama, N., A. Mizutani, N. Hatori, S. Shinada, M. Arai, F. Koyama and K. Iga[1999b], Polarization characteristics of surface emitting laser grown on (311)B substrates under high speed modulation, Trans. IEICE, vol. J82-C-I, no. 7, pp. 421-427

Nishiyama, N., M. Arai, S. Shinada, K. Suzuki, F. Koyama and K. Iga[2000a], Multi-oxide layer structure for single-mode operation in vertical-cavity surface-emitting lasers, IEEE Photon. Technol. Lett., vol. 12, no. 6, pp. 606-608

Nishiyama, N., M. Arai, S. Shinada, T. Miyamoto, F. Koyama and K. Iga[2000b], 1.15 m lasing operation of highly strained GaInAs/GaAs on GaAs (311)B substrate with high characteristic temperature (T0=210 K), Jpn. J. Appl. Phys., vol. 39, no. 10B, pp. L1046-L1047

Nishiyama, N., M. Arai, S. Shinada, T. Miyamoto, F. Koyama and K. Iga[2000c], Growth and optical properties of highly strained GaInAs/GaAs quantum wells on (311)B GaAs by MOCVD, J. Crystal Growth, vol. 221, pp. 530-534

Ohnoki,N., F. Koyama and K. Iga [1998a], Superlattice AlAs/AlInAs-oxide current aperture for long wavelength InP-based vertical-cavity surface-emitting laser structure, Appl. Phys. Lett., vol. 73, no. 22, pp. 3262-3264

Ohnoki, N., F. Koyama and K. Iga[1998b], Super-lattice AlAs/AlInAs for lateral-oxide current confinement in InP-based lasers, J. Crystal Growth, vol. 195, pp. 603-608

Ohnoki, N., G. Okazaki, F. Koyama and K. Iga[1999], Record high characteristic temperature (T0=122K) of 1.55m strain-compensated AlGaInAs/AlGaInAs MQW lasers with AlAs/AlInAs multiquantum barrier, Electron. Lett., vol. 35, no. 1,pp. 51-52

Pan, Z., T. Miyamoto, D. Schlenker, S. Sato, F. Koyama and K. Iga[1998], Low temperature growth of GaInNAs/GaAs quantum wells by metalorganic chemical vapor deposition using tertiarybutylarsine, J. Appl. Phys., vol. 84, no. 11, pp. 6409-6411

Pan, Z., T. Miyamoto, D. Schlenker, F. Koyama and K, Iga[1999], Quality improvement of GaInNAs/GaAs quantum well growth by metalorganic chemical vapor deposition using tertiarybutylarsine ,Jpn. J. Appl. Phys., vol. 38, no. 2B, pp. 1012-1014

Sato, S., N. Nishiyama, T. Miyamoto, T. Takahashi, N. Jikutani, M. Arai, A. Matsutani, F. Koyama and K. Iga[2000], Continuous wave operation of 1.26 &micor;m GaInNAs/GaAs vertical-cavity surface-emitting lasers grown by metalorganic chemical vapour deposition, Electron. Lett., vol. 36, no. 24, pp. 2018-2019

Schlenker, D., T. Miyamoto, Z. Chen, F. Koyama and K. Iga[1999a], 1.17 ?m highly strained GaInAs-GaAs quantum-well laser ,IEEE Photon. Technol. Lett., vol. 11, no. 8, pp. 946-948

Schlenker, D., Z. Pan, T. Miyamoto, F. Koyama and K. Iga[1999b], Effect of surface quality on overgrowth of highly strained GaInAs/GaAs quantum wells and improvement by a strained buffer layer ,Jpn. J. Appl. Phys., vol. 38, no. 9A, pp. 5023-5027

Schlenker, D., T. Miyamoto, Z. Pan, F. Koyama and K. Iga[1999c], Miscibility gap calculation for Ga1-xInxNyAs1-y including strain effects, J. Crystal Growth, vol. 196, pp. 67-70

Schlenker, D., T. Miyamoto, Z. Chen, F. Koyama and K. Iga[2000a], Growth of highly strained GaInAs/GaAs quantum wells for 1.2m wavelength lasers, J. Crystal Growth, vol. 209, pp. 27-36

Schlenker, D., T. Miyamoto, Z. Chen, M. Kawaguchi, T. Kondo, E. Gouardes, J. Gemmer, C. Gemmer, F. Koyama and K. Iga[2000b], Inclusion of strain effect in miscibility gap calculations for III-V semiconductors, Jpn. J. Appl. Phys., vol. 39, no. 10, pp. 5751-5757

Schlenker, D., T. Miyamoto, Z. Chen, M. Kawaguchi, T. Kondo, E. Gouardes, F. Koyama and K. Iga[2000c], Critical layer thickness of 1.2m highly strained GaInAs/GaAs quantum wells, J. Crystal Growth, vol. 221, pp.503-508

Sekiguchi, S., T. Kimura, T. Miyamoto, F. Koyama and K. Iga[1999a], Long wavelength GaInAsP lasers with n-n contacts using AlAs/InP hole injecting tunnel junction, Jpn. J. Appl. Phys., vol. 38, no. 4B, pp. L443-L445

Sekiguchi, S., T. Miyamoto, T. Kimura, F. Koyama and K. Iga[1999b], Self-aligned current confinement structure using AlAs/InP tunnel junction in GaInAsP/InP semiconductor lasers ,Appl. Phys. Lett., vol. 75, no.11, pp. 1512-1514

Sekiguchi, S., T. Miyamoto, T. Kimura, G. Okazaki, F. Koyama and K. Iga[2000], Improvement of current injection uniformity and device resistance in long-wavelength vertical-cavity surface-emitting laser using a tunnel junction, Jpn. J. Appl. Phys., vol. 39, no. 7A, pp. 3997-4001

Shinada, S., F. Koyama, N. Nishiyama, M. Arai, K. Goto and K. Iga[1999a], Fabrication of micro-aperture surface emitting laser for near field optical data storage, Jpn. J. Appl. Phys., vol. 38, no. 11B, pp. L1327-L1329

Shinada, S., F. Koyama, K. Suzuki, K. Goto and K. Iga[1999b], Near-field analysis of micro-aperture surface emitting laser for high density optical data storage, Optical Review, vol. 6, no. 6, pp. 486-488

Shinada, S., F. Koyama, N. Nishiyama, M. Arai, A. Matsutani, K. Goto and K. Iga[2000], Optical near field by vertical cavity surface emitting laser, Trans. IEICE, vol. J83-C, no. 9, pp. 826-833

Shirasawa, T., T. Honda, N. Mochida, A. Inoue, T. Sakaguchi, F. Koyama and K. Iga[1998], Interface control of GaN/AlGaN quantum well structures in MOVPE growth, J. Crystal Growth, vol. 180/190, pp. 124-127

Takahashi, T., T. Katayama and K. Iga[2000], Optical pattern recognition system based on parallel spatial filtering using synthetic discriminant function, Jpn. J. Appl. Phys., vol. 39, no. 3B, pp. 1571-1575

Takeuchi, K., A. Matsutani, F. Koyama and K. Iga[2000], Improvement of AlAs selective oxidation process for GaAs/GaAlAs vertical cavity surface emitting lasers and their single-mode lasing characteristics ,Trans. IEICE, vol. J83-C, no. 9, pp. 904-907

Yamatoya,T., S. Mori, F. Koyama and K. Iga[1999], High power GaInAsP/InP strained quantum well superluminescent diode with tapered active region ,Jpn. J. Appl. Phys., vol. 38, no. 9A, pp. 5121-5122

Yamatoya, T., F. Koyama and K. Iga[2000], Noise suppression and intensity modulation in gain-saturated semiconductor optical amplifiers and its application to spectrum-sliced light sources, Jpn. J. Appl. Phys., vol. 39, no. 8B, pp. L861-L863

D2. Optical Devices for Optical Fiber Networks
Aozasa, S., H. Masuda, H. Ono, T. Sakamoto, K. Kanamori, Y. Ohoshi and M. Shimizu[2001], 1480-1510 nm-band Tm doped fiber amplifi, er (TDFA) with a high power conversion effieiency of 42 %, Tech. Digest of OFC2001, Postdeadline papers PD1

Fukuchi, K., T. Kasamatsu, M. Morie, R. Ohhira, T. Ito K. Sekiya, D. Ogasahara and T. Ono[2001], 10.92-Tb/s(273 x 40-Gb/s) triple-band/ultra-dense WDM optical-repeated transmission experiment, Tech. Digest of OFC 2001, paper PD24

Goh, T., M. Yasu, K. Hattori, A. Himeno and Y. Ohmori[2001], Y., Low loss and high extinction ratio strictly nonblocking 16x16 thermo-optic matrix switch on 6-in wafer using silica-based planar lightwave circuit technology, J. Lightwave Technol., vol. 19, no. 3, pp.371-379

Hida, Y., Y. Hibino, T. Kitoh, Y. Inoue, M. Itoh, T. Shibata, A. Sugita and A. Himeno[2001], 400-channel arrayed-waveguide grating with 25 GHz spacing using 1.5%-D waveguide on 6-inch Si wafer, Electron. Lett., vol. 37, no. , pp.576-577

Ishizuki, H., M. Fujimura, T. Suhara and H. Nishihara[2000], LiNb03 waveguide quasi-phase-matched sum-frequency generation device for high-efficiency optical sampling", IEICE vol. J83-C, pp.197-203

Jinguji, K. and M. Oguma[2000], Optical half-band filters, IEEE J. Lightwave Technol., vol. 18, no.2, pp. 252-259

Kawanishi. S. [1998], Ultrahigh-Speed Optical Time-Division-Multiplexed Transmission Technology based on optical Signal Processing, IEEE Journal of Quantum Electronics, vol. 34, no. 11, pp. 2064-2079

Kubota, H., K. Suzuki, S. Kawanishi, M. Nakazawa, M. Tanaka and M. Fujita[2001], Low-loss, 2 km-long photonic crystal fiber with zero GVD in the near IR suitable for picosecond pulse propagation at the 800 nm band, Tech. Digest of CLEO 2001, paper CPD3

Noda, S., N. Yamamoto, M. Imada, H. Kobayashi and M. Okano[1999], Alignment and stacking of semiconductor photonic bandgaps by wafer-fusion, IEEE J. Lightwave Technol., vol. 17, no. 11, pp. 1948-1955

Okuno, M., K. Kato, R. Nagase, A. Himeno, Y. Ohmori and M. Kawachi[1999], Silica-based 8x8 optical matriz switch integrating new switching units with large fabrication tolerance, J. Lightwave Technol., vol.17 ,no.5, pp.771-781

Sato,K. and S. Okamoto[1999], Photonic transport technologies to create robust backbone networks, IEEE Communications Magazine, vol. 37, no. 8, pp. 78-87

Takada, K., M. Abe, T. Shibata, M. Ishii, Y. Inoue, H. Yamada and Y. Hibino [2000], 10 GHz-spaced 1010-channel AWG filter achieved by tandem connection of primary and secondary AWGs, Proc. ECOC2000, Postdead-line paper PD3-8

Takara, H., T. Ohara, K. Mori, K. Sato, E.Yamada, K. Jinguji, Y. Inoue, T. Shibata, T. Morioka and K-I Sato[2000], Over 1000 channel optical frequency chain generation from a single supercontinuum source with 12.5 GHz channel spacing for DWDM and frequency standards, Tech. Digest of ECOC 2000, paper PD3.1

Takiguchi, K., K.Okamoto and T. Goh[2001], Planar lightwave circuit dispersion slope equalizer for N x 40 Gb/s WDM transmission, Electron. Lett., vol. 37, no. 11, pp. 701-703

Tsuritani, T., Y. Yamada, A. Agata, N. Takeda, N. Edagawa and M. Suzuki[2000], 1 Tbit/s (100 x 10.7 Gbit/s) transpacific transmission using single-stage 980 nm-pumped C-band optical repeaters without forward error correction", Electron. Lett., vol. 36, no. 18, pp. 1566-1568

Yamabayashi, Y., M. Koga and S. Okamoto[2000], Autonomously controlled multiprotocol wavelength switching network for Internet backbones, IEICE Trans. Commun., vol. E83-B, no. 10, pp. 2210-2215

Yoneyama. M., Y. Miyamoto, T. Otsuji, H. Toba, Y. Yamane, T. Ishibashi and H. Miyazawa[2000], Fully electrical 40-Gb/s TDM system prototypebased on InP HEMT digital IC technologies, IEEE J. Lightwave Technol., vol. 18., no. 1, pp. 34-42

D3. Femtosecond Technology
Akiyama, T., O. Wada, H. Kuwatsuka, T. Shimoyama, Y. Nakata, K. Mukai, M. Sugawara and H. Ishikawa[2000],Nonlinear processes responsible for nondegenerate Four-Wave Mixing in Quantum-Dot optical amplifier, Applied Physics Letters, vol.77, no.12, pp.1753-1755

Akiyama, T., N. Georgiev, T. Mozume, H. Yoshida, A.V. Gopal and O. Wada[2001], Nonlinearity and recovery time of 1.55 m intersubband absorption in InGaAs/AlAs/AlAsSb coupled quantum wells, Electronics Letters, vol.37, no.2, pp.129-130

Furuki, M., M. Tian, Y. Sato, L. S. Pu, S. Tatsuura and O. Wada[2000], Terahertz demultiplexing by a Single-Shot Time-to-Space conversion using a film of squarylium Dye J-Aggregates ,Applied Physics Letters, vol.77, no.4, pp.472-474

Iizuka, N., K. Kaneko, N. Suzuki, T. Asano, S. Noda and O. Wada[2000],Ultrafast intersubband relaxation (<150 fs) in AlGaN/GaN multiplequantum wells, Applied Physics Letters, vol.77, no.5, pp.648-650

Lan, S., S. Nishikawa and O. Wada[2001], Leveraging deep photonic bandgaps in photonic crystal impurity bands, Applied Physics Letters, vol.78, no.15, pp.2101-2103

Wada, O. and H. Hasegawa ed.[1999a], InP-Based Materials and Devices -Physics and Technology- , John Wiley & Sons, New York

Wada, O., A. Suzuki, Y. Ogawa and K. Tajima[1999b], Chapter III-1 Femtosecond Semiconductor-Based Optoelectronic Devices for Optical Communications and Signal-Processing Systems, pp. 59-78, in T. Kamiya, H. Yajima, F. Saito and O. Wada ed., Femtosecond Technology -From Basic Research to Application Prospects-, Springer-Verlag, Berlin

Wada, O., H. Yoshida, A. Neogi, T. Akiyama, T. Mozume, N. Georgiev and K. Asakawa[2000a],Ultrafast intersubband absorption switching using InGaAs/AlAsSb quantum wells, International Conf. on Indium Phosphide and Related Materials, Williamsburg, Conf. Proc., pp. 431-434

Wada, O.[2000b], Femtosecond Semiconductor-Based optoelectronic devices for optical communications systems[Invited Paper], Optical and Quantum Electronics, vol.32, no. , pp.453-471

Wada, O.[2000c], Femtosecond All-Optical Devices for Tera-bit optical information networks [Invited Paper], International Electron Devices Meeting, IEDM00, San Francisco, U.S.A., Tech. Dig., pp. 589-592

D4. Ultrafast Phenomena
Chin, B.C., K. Misawa, T. Masuda and T. Kobayashi[2000], Large static dipole moment in substituted polyacetylenes obtained by electroabsorption, Chem. Phys. Lett., vol.318, pp.499-504

Deng, Z.-Y., T. Kobayashi and T. Ohji[1999a], Optical absorption spectra in a three-dimensional corner under anapplied electric field, J. Phys.: Condens. Matter, vol. 11, no.29, pp.5583-5591

Deng, Z. -Y., J.-L. Shi, Y.-F. Zhang, J.-K.Fuo and T. Kobayashi[1999b], Microstructure and creep behavior of Al2O3-SiC ceramic matrix composites, Key Eng. Matel., vol.159-160, pp.399-404

Deng, Z.-Y., X. Chen, T. Ohji and T. Kobayashi[2000], Subband structures, exciton and impurity states in V-shapedGaAs-Ga1-xAlxAs quantum wires, Phys. Rev. B, vol.61, no.23, pp.15905-15913

Fuji, T., T. Saito and T. Kobayashi[2000], Dynamic observation of Duschinsky rotation by sub-5-fs real-time spectroscopy, Chem. Phys. Lett., vol.332, pp.324-330

Guan Z.P. and T. Kobayashi[1999], Electroreflection from higher subband transitions in a ZnSe-Zn0.8Cd0.2Se superlattice, Solid State Commun. vol.111, no.6, pp.311-316

Hashimoto, H., H. Takahashi, T. Yamada, K. Kuroyanagi and T.Kobayashi[2001], Characteristics of the terahertz radiation from single crystals of N-substituted 2-methyl-4-nitroaniline, J. Phys.:Condens. Matt., vol.13, pp.L529-L537

Hofmann, H.F., T. Kobayashi and A.Furusawa[2000a], Nonclassical correlation of photon number and field components in the vacuum state, Phys. Rev. A, vol.62, no.013806

Hofmann, H.F., T. Ide, T. Kobayashi and A. Furusawa[2000b], Fidelity and information in the quantum teleportation of continuous variables, Phys. Rev. A, vol.62, no.062304

Hofmann H.F. and T. Kobayashi[2000c], Nonclassical correlation of phase noise and photon number in quantum nondemolition measurements, Phys. Rev. A, no.033815

Hofmann, H.F., T. Kobayashi and A. Furusawa[2001], Information losses in continuous variable quantum teleportation, Phys. Rev., vol.64, no.40301

Kamiya, N., H. Ohtani, T. Sekikawa and T. Kobayashi[1999], Sub-picosecond fluorescence spectroscopy of the M intermediateformed in the photocycle of bacteriorhodopsin by using up-conversion fluorometry, Chem. Phys. Lett., vol.305, no.1,2, pp.15-20

Kano H. and T. Kobayashi[2000a], Simultaneous measurement of real and imaginary parts of nonlinear susceptibility for the verification of the Kramers-Kronig relations in femtosecond spectroscopy, Opt. Comm., vol.178, pp.133-139

Kano H. and T. Kobayashi[2000b], Time-resolved fluorescence spectroscopy of porphyrin J-aggregates using optical Kerr gate methods, J. Chin. Chem. Soc., vol.47, pp.859-861

Kano, H., K. Misawa and T. Kobayashi[2001a], Periodic structures in difference phase and transmission spectra studied by a femtosecond Sagnac interferometer, Opt. Commun., vol.188, pp.1-9

Kano, H., T. Saito and T. Kobayashi[2001b], Dynamic intensity borrowing in porphyrin J-aggregates revealed by sub-5-fs spectroscopy, J. Phys. Chem., vol.105, pp.413-419

Kobayashi, T.[1999], Structure and nonlinear properties of porphyrin J-aggregates, Nonlin. Opt., vol.22, pp.301-304

Kobayashi, T., A. Shirakawa, H. Matsuzawa and H. Nakanishi[2000a], Real-time vibrational mode-coupling associated with ultrafast geometrical relaxation in a polydiacetylene induced by sub-5-fs pulses, Chem. Phys. Lett., vol.321, no.5-6, pp.385-393

Kobayashi, T. and A. Shirakawa[2000b], Tunable visible and near-infrared pulse generation in a 5 fs regime, Appl. Phys. B, vol. 70, pp.S239-S246

Kobayashi, T and A. Shirakawa[2000c], Sub-5-fs tunable pulses in visible and nir visible sub-5-fs pulses generated by noncollinear opa, J. Luminescence, vol.87-89, pp.119-120

Kobayashi, T., A.Shirakawa and T. Fuji[2001a], Sub-5-fs transform-limited visible pulse source and its application to real-time spectroscopy, IEEE Journal of Selected Topics in Quantum Electron, vol.7, no.4, pp.525-538

Kobayshi,T., T.Saito and H.Ohtani[2001b], Real-time spectroscopy of transition states in bacteriorhodopsin during retinal isomerization, Nature, vol.414,pp. 531-534

Misawa, K. and T. Kobayashi[1999], Ultrafast exciton excited-exciton dynamics in J-aggregates of three-level porphyrin molecules, J. Chem. Phys., vol.110, no.12, pp.5844-5850

Misawa K. and T. Kobayashi[2000], Wave-packet dynamics in a cyanine dye molecule excited with femtosecond chirped pulses, J. Chem. Phys., vol.113, no.7, pp.7546-7553

Shirakawa, A., I. Sakane, M. Takasaka and T. Kobayashi[1999], Sub-5-fs visible pulse generation by pulse-front-matched noncollinear optical parametric amplifier, Appl. Phys. Lett., vol.74, no.12, pp.2268-2270

Sugita, A., T. Saito, H. Kano, M. Yamashita and T. Kobayashi[2001a], Wave packet dynamics in a quasi-one-dimensional metal-halogen complex studiedby sub-5-fs spectroscopy, Phys. Rev. Lett., vol.86, pp.2158-2161

Sugita, A., M. Yamashita and T. Kobayashi[2001b], Ultrafast relaxation dynamics of neutral soliton pairs in a quasi-one-dimensional halogen-bridged mixed-valence platinum complex Pt(en)2[Pt(en)2Br2](ClO4)4, J. Chem.Phys., vol.114, pp.2369-2376

Sugita, A. and T.Kobayashi[2001c], Dynamics of a photo-excited state in polydiacetylene studied by femtosecond mid-infrared absorption spectroscopy, Chem. Phys. Lett., vol.346, pp.41-46

Sun, R., Q. Zheng, X. Zhang T. Masuda and T. Kobayashi[1999], Light-emitting substituted polyacetylenes, Jpn. J. Appl. Phys., vol.38, no.4A, pp.2017-2023

Ullrich,B., T. Loeher, Y. Segawa and T. Kobayashi[1999], The influence of hydrogen passivation of silicon on the photocurrent of Cd/Si heterodiodes, Mater. Sci. and Engin., no.B56, pp.150-152

Yabushita, A., T.Fuji and T.Kobayashi[2001], SHG FROG and XFROG methods for phase/intensity characterization of pulses propagated through an absorptive optical medium, Opt. Commun., vol.198, pp.227-232

Yamamoto, K., T. Kamata, S. Iwai, S. Kazaoui, N. Minami, F. Mizukami, K. Misawa, T. Ohta and T. Kobayashi[1999], Franz-Keldysh oscillation in the interband absorption spectrum of one-dimensional bis(dimethylglyoximato)platinum(II) complex, Chem. Phys. Lett., vol.302, no.3, pp.609-614
D5. THz Technology
Cho, Y., S. Kazuta, and H. Ito [2001], Scanning-nonlinear-dielectric-microscopy study on periodically poled LiNbO3 for a high-performance quasi-phase matching device, Applied Physics Letters, vol.79, no.18, pp.2955-2957

Haidar, S., K. Nakamura, E. Niwa, K. Masumoto, and H. Ito [1999a], Mid-infrared (5-12-mm) and limited (5.5-8.5-mm) single-knob tuning generated by difference-frequency mixing in single-crystal AgGaS2, Applied Optics, vol.38, no.9, pp.1798-1801

Haidar, S., and H. Ito [1999b], Injection-seeded optical parametric oscillator for efficient difference frequency generation in mid-IR, Optics Communication, vol.171, pp.171-176

Hatanaka, T., K. Nakamura, T. Taniuchi, H. Ito, Y. Furukawa, and K. Kitamura [2000a], Quasi-phase-matched optical parametric oscillation with periodically poled stoichiometric LiTaO3, Optics Letters, vol.25, no.9, pp.651-653

Hatanaka, T., K. Nakamura, T. Taniuchi, and H. Ito [2000b], Dual signal-wave optical parametric oscillator using periodically poled LiNbO3 with series gratings, Electronics Letters, vol.36, no.16, pp.1409-1411

Imai, K., K. Kawase, J. Shikata, H. Minamide, and H. Ito [2001], Injection-seeded terahertz-wave parametric oscillator, Applied Physics Letters, vol.78, no.8, pp.1026-1028

Ito, H., T. Hatanaka, S. Haidar, K. Nakamura, K. Kawase, and T. Taniuchi [2001], Periodically Poled LiNbO3 OPO for Generating Mid IR to Terahertz Waves, Ferroelectrics, vol.253, pp.95-104

Kawase, K., M. Mizuno, S. Sohma, H. Takahashi, T. Taniuchi, Y. Urata, S. Wada, H. Tashiro, and H. Ito [1999], Difference-frequency terahertz-wave generation from 4-dimethylamino-N-methyl-4-stilbazolium-tosylate by use of an electronically tuned Ti:sapphire laser, Optics Letters, vol.24, no.15, pp.1065-1067

Kawase, K., T. Hatanaka, H. Takahashi, K. Nakamura, T. Taniuchi, and H. Ito [2000], Tunable THz-wave generation from DAST crystal using dual signal-wave parametric oscillation of periodically poled lithium niobate, Optics Letters, vol.25, no.23, pp.1714-1716

Kawase, K., J. Shikata, K. Imai, and H. Ito [2001a], A transform-limited, narrow-linewidth, THz-wave parametric generator, Applied Physics Letters, vol.78, no.19, pp.2819-2821

Kawase, K., J. Shikata, H. Minamide, K. Imai, and H. Ito [2001b], Arrayed silicon prism coupler for a THz-wave parametric oscillator, Applied Optics, vol.40, no.9, pp.1423-1426

Nakamura, K., T. Miyahara, M. Yoshida, T. Hara, and H. Ito [1998], A new technique of optical ranging by a frequency-shifted feedback laser, IEEE Photonics Technology Letters, vol.10, no.12, pp.1772-1774

Nakamura, K., T. Hara, M. Yoshida, T. Miyahara, and H. Ito [2000], Optical frequency domain ranging by a frequency-shifted feedback laser, IEEE Journal of Quantum Electronics, vol.36, no.3, pp.305-316

Nakazawa, M [2000a], Solitons for breaking barriers to terabit/second WDM and OTDM transmission in the next Millennium, IEEE J. Selected Topics in Quantum Electronics (Millennium Issue invited paper), vol.6, no.6, pp.1332-1343

Nakazawa M., and E. Yoshida [2000b], A 40 GHz, 850 fs regeneratively FM mode-locked polarization-maintaining erbium fiber ring laser, IEEE Photon. Tech. Lett., vol.12, no.12, pp.1613-1615

Nakazawa, M., and K. Suzuki [2001], Cesium optical atomic clock: an optical pulse that tells the time, Optics Letters, vol.26, pp.635-637

Sashinaka, N., Y. Oguma, and M. Asada [2000], Observation of terahertz photon-assisted tunneling in triple-barrier resonant tunneling diodes integrated with patch antenna, Jpn. J. Appl. Phys, vol.39, part.1, no.8, pp.4899-4903

Sato, A., K. Kawase, H. Minamide, S. Wada, and H. Ito [2001], Tabletop terahertz-wave parametric generator using a compact, diode-pumped Nd:YAG laser, Review of Scientific Instruments, vol.72, no.9, pp.3501-3504

Sato, M., T. Hatanaka, S. Izumi, T. Taniuchi, and H. Ito [1999], Generation of 6.6-m optical parametric oscillation with periodically poled LiNbO3, Applied Optics, vol.38, no.12, pp.2560-2563

Shikata, J., M. Sato, T. Taniuchi, and H. Ito [1999a], Enhancement of terahertz-wave output from LiNbO3 optical parametric oscillators by cryogenic cooling, Optics Letters, vol.24, no.4, pp.202-204

Shikata, J., K. Karino, H. Ito, and K. Kawase [1999b], Tunable terahertz-wave generation from MgO:LiNbO3 optical parametric oscillator, OSA Trends in Optics and Photonics Series, vol.26, pp.481-486

Shikata, J., K.Kawase, K.Karino, T.Taniuchi, and H.Ito [2000], Tunable THz-wave parametric oscillation using LiNbO3 and MgO:LiNbO3 crystals, IEEE Trans. on Microwave Theory and Techniques, vol.48, no.4, pp.653-661

Sohma, S., H. Takahashi, T. Taniuchi, and H. Ito [1999], Organic nonlinear optical crystal DAST growth and its device applications, Chemical Physics, vol.245, no.1-3, pp.359-364

Suhara, T., H. Ishizuki, M. Fujimura, and H. Nishihara [1999], Waveguide quasi-phase matched sum-frequency generation device for high-efficiency optical sampling, IEEE Photon. Tech. Lett., vol.11, no.8, pp.1027-1029

Suhara, T., T. Fujieda, M. Fujimura, and H. Nishihara [2000], Fabrication of Zn:LiNbO3 waveguides by diffusing ZnO in low-pressure atmosphere, Jpn. J. Appl. Phys. 2, Lett., vol.39, no.8B, pp.L864-L865

Taniuchi, T., J. Shikata, and H. Ito [2000], Tunable terahertz-wave generation in DAST crystal with dual-wavelength KTP optical parametric oscillator, Electronics Letters, vol.36, no.16, pp.1414-1416

Walther, M., K. Jensby, S. R. Keiding, H. Takahashi, and H. Ito [2000], Far-infrared properties of DAST, Optics Letters, vol.25, no.12, pp.911-913

Yoshida, M., K. Nakamura, and H. Ito [2001a], A new method for measurement of group velocity dispersion of optical fibers by using a frequency-shifted feedback fiber laser, IEEE Photonics Technology Letters, vol.13, no.3, pp.227-229

Yoshida, M., T. Miyamoto, N. Zou, K. Nakamura, and H. Ito [2001b], Novel PMD measurement method based on OFDR using a frequency-shifted feedback fiber laser, Optics Express, vol.9, no.4, pp.207-211
D6. Sensing Photonics
He, Z and K. Hotate[1999a], Measurement of scattering media by synthesis of optical coherence function with superstructure grating distributed Bragg reflector laser diode, Optical Review, vol.6,no.4, pp.372-377

He, Z. and K. Hotate[1999b], Synthesized optical coherence tomography for imaging of scattering objects by use of a stepwise frequency-modulated tunable laser diode, Optics Lett., vol.24,no.21, pp.1502-1504

Hotate, K. and G. Hayashi[1999a], Resonator fiber optic gyro using digital serrodyne modulation -Method to reduce the noise induced by the backscattering and closed-loop operation using digital signal processing-, Proc. Intern. Conf. on Optical Fiber Sensors, Kyongju, pp.104-107 <Invited>

Hotate, K.[1999b], Photonic sensing by use of synthesis of optical coherence function, Proc. URSI GA99, Tront, 26<Invited>

Hotate, K. and T. Hasegawa[2000a], Measurement of Brillouin gain spectrum distribution along an optical fiber using a correlation-based technique -Proposal, experiment and simulation-, IEICE Trans. on Electron., vol.E83-C, no.3, pp.405-412

Hotate, K., Z. He and T. Kitazume[2000b], Surface shape measurement for multi-layered object by synthesis of optical coherence function, J. of Selected Topics in Quantum Electron., vol.6,no.5, pp.723-729

Hotate, K.[2000c], Fiber optic gyros, Proc. Interna. Conf. on Trends in Optical Nondestructive Testing, Lugano, pp.487-502<Invited>

Hotate, K. and M. Tanaka[2000d], Distributed fiber Brillouin strain sensing with 1cm spatial resolution by correlation-based countinuous wave technique, Proc. 14th Intern. Conf. on Optical Fiber Sensors, Venice, pp.647-650<Invited>

Hotate, K. and T. Hasegawa[2000e], A correlation-based continuous-wave technique for measuring Brillouin gain spectrum distribution along an optical fiber with centimeter-order spatial resolution, Proc. 14th Intern. Conf. on Optical Fiber Sensors, Venice, pp.651-661<Invited>

Hotate, K.[2000f], Fiber optic distributed sensing for smart materials and structures by synthesis of optical coherence function, Proc. Intern. Conf. on Processing and Manufacturing of Advanced Materials, Las Vegas<Invited>

Hotate, K., X. Song and Z. He[2001a], Stress-location measurement along an optical fiber by synthesis of triangle-shape optical coherence function, IEEE Photon. Technol. Lett., vol.13,no.3, pp.233-235

Hotate, K. and M. Tanaka[2001b], High-resolution distributed fiber Brillouin strain sensing, Proc. OECC/IOOC 2001, Sydney, pp.271-274<Invited>

Hotate, K. and M. Tanaka[2001c], Correlation-based continuous wave technique of fiber Brillouin distributed strain sensing for smart materials with cm order spatial resolution, Proc. CLEO/Pacific Rim 2001, Chiba, pp.I-496-497<Invited>

Hotate,K[2001d], Correlation-based continuous wave technique for fiber Brillouin distribution sensing with a high spatial resolution, Proc. SPIE Fiber Optical Sensor Technologies and Applications, Boston, pp.4578-03<Invited>

Saida, T. and K. Hotate[1999], General formula describing drift of interferometer fiber-optic gyro due to Faraday effect: Reduction of the drift in twin-depo-I-FOG, IEEE J. of Lightwave Technol., vol.17,no.2, pp.222-228

Suzuki, K., K. Takiguchi and K. Hotate[1999], Reduction of backscattering-induced noise by ternary phase shift keying in resonator micro-optic gyro integrated on silica planar lightwave circuit, IEE Electron. Lett., vol.35,no.13, pp.1076-1077

Suzuki, K., K. Takiguchi and K. Hotate[2000], Monolithically integrated resonator micro optic gyro on silica planar lightwave circuit, J. of Lightwave Technol., vol.18,no.1pp., 66-72

Yamashita, S., K. Hotate and M. Ito[1998], Polarization-independent local node construction for optical WDM ring networks using a centralized multiwavelength light source, IEICE Trans. on Commun., vol.E81-B,no.11, pp.2168-217

Yamashita, S. and K. Hotate[2001], A distributed pressure sensor using a mode-locked fiber ring laser, OSA Optics Lett., vol.26,no.9, pp.590-592

Zhu, B. and K. Hotate[2001], Multiplexed optical fiber interferometric sensor system by synthesis of optical coherence function with phase generated carrier, Optical Review, vol.8,no.2, pp.107-111
D7. Systems Photonics
Arahira, S., Y. Katoh and Y. Ogawa[2001], Generation and stabilization of ultrafast optical pulse trains with monolithic mode-locked laser diodes, Optical and Quantum electronics,vol.33,pp.691-707

Iijima, A., Y. Tanaka, T. Kurokawa[2001], Analysis on Fabry-Perot interferometer using cholesteric liquid crystal, Molecular crystals and liquid crystals, vol.368, pp.37-41

Inaba, R., N. Kawakami, K. Oguma, E. Watanabe and K. Kodate[2000], Compact parallel joint transform correlator for facial recognition, Proc. SPIE,vol.4089,pp.384-392

Ishibashi S. and H. Takahara[1999], Optical waveguide components using fluorinated polyimide, Proc. SPIE,vol.3799,pp.254-265

Kinoshita, M., M. Takeda, H. Yago, Y. Watanabe and T. Kurokawa[1999], Optical frequency-domain imaging microprofilometry with a frequency-tunable liquid-crystal Fabry-Perot etalon device, Appl. Opt., vol.38 ,no.34, pp. 7063-7068

Kodate, K., A. Hashimoto and R. Thapliya[1999], Binary zone-plate array for a parallel joint transform correlation to face recognition, Appl. Opt.,vol.38,pp.3036

MacDonald, R.P., S. A. Boothroyd, P. Myslinski, R. Misner, B. A. Syrett and T. Kurokawa[2001], 1x16 amplifier array and hybrid integration with an 8x8 p-i-n photodiode array for parallel optical interconnects, Microwave Opt. Technol. Lett., vol.28 ,no.1, pp.11-15

Nakahara, T., H. Tsuda, K. Tateno, S. Matsuo and T. Kurokawa[1999], Hybrid integration of smart pixels by using polyimide bonding, IEEE J . Selected Topics in Quantum Electron., vol.5 ,no.2, pp.209-216

Nishimura, S., T. Kudoh, H. Nishi, K. Harasawa, N. Matsui, S. Akutsu, K. Tasyo and H. Amano[2000], High-throughput network switch for the RHiNET-2 optically interconnected parallel computing system, Proc. SPIE,vol.4089,pp.562-569

Okabe Y. and H. Sasaki[2001], Wide-channel-spacing wavelength division multiplexer and demultiplexer consisting of stacked dielectric filters and diffractive optical elements, Technical Digest of 8th Microoptics Conference -MOC2001-,pp.338-341

Sano, M., M. Takeda, S. Fukushima and T. Kurokawa[1998], Real-time holographic vibrometry with a ferroelectric liquid-crystal spatial light modulator, Appl. Opt.,vol.37 ,no.32, pp.7523-7531

Sano, Y., J. Mita, T. Yamada, T. Makita, K. Kaifu, H. Ishikawa, T. Egawa and T. Jimbo[2001], High Performance AlGaN/GaN HEMTs with Recessed Gate, Technical Digest of International Conference on SiC and Related Materials -ICSCRM2001-,pp.689-690

Sasaki, H., K. Kotani, H. Wada, T. Takamori and T. Ushikubo[2001a], Scalability analysis of diffractive optical element-based free-space photonic circuits for inter-optoelectronic chip, Appl. Opt.,vol.40,pp.1843-1855

Sasaki, H., S. Takasaki, K. Kotani and T. Takamori[2001b], Compact bidirectional photonic circuit employing stacked multilayers of diffractive optical elements for fiber to the home applications, Proc. SPIE,vol.4437,pp.108-118

Takenouchi, H., H. Tsuda, K. Naganuma, T. Kurokawa, Y. Inoue and K. Okamoto [1998], Differential processing of ultrashort optical pulses using arrayed-waveguide grating with phase-only filter, Electron.. Lett., vol.34,no12, pp. 1245-1246

Takenouchi, H., H. Tsuda, T. Goh, K. Okamoto, C. Amano and T. Kurokawa[1999], Differential processing using an arrayed-waveguide grating, IEICE Trans. Commun., vol.E82-B ,no.8, pp. 1252-1258

Takenouchi, H., H. Tsuda and T. Kurokawa[2000], Analysis of optical-signal processing using an arrayed-waveguide grating, Optics Express, vol.6, p.124

Tsuda, H., K. Okamoto, T. Ishii, K. Naganuma, Y. Inoue, H. Takenouchi and T. Kurokawa[1999a], Second- and Third-order dispersion compensator using a high-resolution arrayed-waveguide grating, IEEE Photon. Technol. Lett., vol.11,no.5, pp. 569-571

Tsuda, H., H. Takenouchi, T. Ishii, K. Okamoto, T. Goh, K. Sato, A. Hirano, T. Kurokawa and C. Amano[1999b], Spectral encoding and decoding of 10Gbit/s femtosecond pulses using high-resolution arrayed-waveguide grating, Electron. Lett., vol.35 ,no.14, pp. 1186-1188

Tsuda, H., H. Takenouchi, T. Kurokawa and K. Okamoto[2000a], Performance analysis of a dispersion compensator using arrayed-waveguide gratings, IEEE J. Lightwave Technol., vol.18 ,no.8, pp.1139-1147

Tsuda H. and T. Kurokawa[2000b], Smart pixels and their applications to optical interconnects (Invited Paper) ,Proceeding of SPIE, vol.4225, pp.364-369

Tsuda H. and T. Kurokawa [2001], Optical information processing using arrayed-waveguide grating and its application to optical communication systems, Proc. SPIE,vol.4513,pp.101-106

Uenohara, H., K. Tateno, T. Kagawa, Y. Ohiso, H. Tsuda, T. Kurokawa and C. Amano[1999a], Investigation of dynamic polarization stability of 850-nm GaAs-based vertical-cavity surface-emitting laser grown on (311)B and (100) substrates, IEEE Photon. Technol. Lett., vol.11 ,no.4, pp. 400-402

Uenohara, H., K. Tateno, T. Kagawa, Y. Ohiso, H. Tsuda, T. Kurokawa and C. Amano[1999b],Polarization-controlled 850-nm-wavelength vertical-cavity surface-emitting lasers grown on (311)B substrates by metal-organic chemical vapor deposition, IEEE J. Selected Topics in Quantum Electron., vol.5 ,no.3, pp.537-545

Wada, H., H. Sasaki and T. Kamijoh[1999], Wafer bonding technology for optoelectronic integrated devices, Solid-State Electronics,vol.43,pp.1655-1663
D8. Microwave Photonics
Hoshida, T. and M. Tsuchiya[1998], "Broadband Millimeter-Wave upconversion by nonlinear Photo-detection using a waveguide p-i-n photodiode", IEEE Photonics Technology Letters, vol.10,no.6, pp.860-862

Ozeki, Y., K. Nishikawa, M. Kishi and M. Tsuchiya[2001a], 60 GHz optoelectronic image rejection mixer and its application to a 156 Mb/s Fiber-Optic MM-Wave Link, Photon. Technol. Lett.,vol.13,no.4,pp.361-363

Ozeki, Y., K. Higuma, S. Oikawa, M. Kishi and M. Tsuchiya[2001b], A 60 GHz optoelectronic mixing scheme of high image and carrier rejection ratios with an integrated optical Single-Sideband modulator employed ,IEEE MTT Special Issue on MWP, vol. 49, no. 10, pp. 1986-1991

Tsuchiya, M., T. Hoshida and T. Kamiya[1998], Passively Mode-Locked semiconductor lasers stabilized by subharmonic electrical injection and their application to millimeter wave photonics, New Trend in Optical Soliton Transmission Systems, Proceedings of the Symposium held in Kyoto, Japan, 1997, pp. 403-418 (Kluwer Academic Publishers, Dordrecht, The Netherland, 1998)

Tsuchiya, M. and T. Hoshida[1999], Nonlinear photodetection scheme and its system applications to fiber-optic millimeter-wave wireless down-links, Special Issue of the IEEE Transactions on Microwave Theory and Techniques on Microwave and Millimeter-wave Photonics, vol. 47, no. 7, pp. 1342-1350

Wakana, S., T. Ohara, M. Abe, E. Yamazaki, M. Kishi and M. Tsuchiya[2000], Fiber edge electro/magneto-optic probe for spectral domain analysis of electromagnetic field, IEEE MTT, vol. 48, no. 12, pp. 2611-2616