To meet the requirements of millimeter-wave applications such as satellite communications, local bi-directional communications, and automotive radars, several MMICs have been developed mainly using hetero-structure devices. In Ka-band, a switched-line phase shifter MMIC incorporating unresonated switches demonstrated a phase deviation of 3.3deg rms at 34.5 GHz. The circuit was fabricated with 0.15-mm T-shaped-gate HJFETs [Maruhashi et al., 1998a]. Two-stage low-noise amplifier MMIC achieved a noise figure of 1.0 dB with an associated gain of 18.0dB at 32GHz, using a AlGaAs/InGaAs/GaAs pseudomorphic HEMT with a gate length of 0.15mm [Fujimoto et al., 1997]. A 38GHz-band monolithic voltage controlled oscillator exhibited a phase noise of 85dBc/Hz at a 100kHz offset and an output power of 8.4dBm. The circuit was designed with an AlGaAs/InGaAs HBT with p+/p regrown base contacts[Tanji et al., 1998]. A V-band MMIC chip set consisting of a receiver MMIC with a noise figure of 6.5dB and a transmitter MMIC with an output power of 17.7dBm has been developed with HJFETs[Mizoe et al., 1997]. A W-band T/R MMIC chip set for automotive radar systems has been fabricated using psuedomorphic HEMT with a gate length of 0.15mm[Kamozaki et al., 1997].
Cost reduction is the key to the millimeter-wave market. Several methods have been proposed for low-price high-frequency systems. Flip-chip technology was employed to realize low-cost MMIC assembly. For 76GHz automotive radar systems, a flip-chip bonded amplifier has been developed [Murahashi et al.,1998b][Hirose et al., 1998]. The chip set has also been fabricated using flip-chip packages and HEMTs with a gate length of 0.15mm[Ohashi et al., 1998]. A master-slice architecture is another approach for cost reduction, which is popular in digital circuits. A V-band amplifier has been demonstrated with a three-dimensional MMIC master-slice structure and heterojunction MESFETs, obtaining a noise figure of 5.3dB [Nishikawa et al., 1998].
As an emerging device technology, resonant tunneling diodes and HEMTs have been integrated in a monolithic injection-locked oscillator. Due to the strong nonlinear characteristics of resonant tunneling diodes, the circuit can be locked for 128 higher-order subharmonics[Kamogawa et al., 1998]. The wafer-scale MMIC approach has been proposed as an advanced technology [Toyoda et al., 1996].
Bito, Y., N. Iwata, and M. Tomita, "64% Efficiency enhancement-mode power heterojunction FET for 3.5 V Li-ion battery operated personal digital cellular phones," IEEE 1998 MTT-S IMS, pp. 439-442
Choumei, K., K. Yamamoto, N. Kasai, T. Moriwaki, Y. Yoshii, T. Fujii, J. Otsuji, Y. Miyazaki, T. Tanino, and K. sato, "A highefficiency, 2V single-supply voltage operation RF front-end MMIC for 1.9GHz personal handy phone systems," IEEE GaAs Symposium 1998, pp.73-76
Fujimoto, S., T. Katoh, T. Ishida, T. Oku, Y. Sasaki, T. Ishikawa and Y. Mitsui, "Ka-band ultra low noise MMIC amplifier using pseudomorphic HEMTs," IEEE 1997 MTT-S IMS, pp. 17-20
Hirose, T., K. Makiyama, T. M. Shimura, S. Aoki, Y. Ohashi, S. Yokokawa, and Y. Watanabe, "A flip-chip MMIC design with CPW technology in the W-band," IEEE 1998 MTT-S IMS, pp. 525-538
Iwai, T., S. Ohara, T. Miyashita, and K. Joshin," 63.2% high efficiency and high linearity two-stage InGaP/GaAs HBT power amplifier for personal digital cellular phone system," IEEE 1998 MTT-S IMS, pp. 435-438
Kamogawa, K., I. Toyoda, T. Tokumitsu, H. Fukuyama, M. Yamamoto, and M. Tanaka, "A very high-order subharmonically injection-locked oscillator using a resonant-tunneling HEMT," EuMC 1998, vol. 1, pp. 395-399
Kamozaki, K., N. Kurita, W. Hioe, T. Tanimoto, H. Ohta, T. Nakamura, and H. Kondoh, "A 77GHz T/R MMIC chip set for automotive radar systems," IEEE GaAs Symposium 1997, pp.275-278
Maruhashi, K., H. Mizutani, and K. Ohata[1998a]," A Ka-band 4-bit monolithic phase shifter using unresonated FET switches," IEEE 1998 MTT-S IMS, pp. 1095-1098
Maruhashi K. , M. Ito, H. Kusamitsu, Y. Morishita and K. Ohata[1998b], "RF performance of a 77GHz monolithic CPW amplifier with flip-chip interconnections," IEEE 1998 MTT-S IMS, pp. 1095-1098
Matsuno, N., H. Yano, Y. Suzuki, T. Watanabe, K. Tanaka, and K. Honjo, "Development of a Si MOS MMIC power amplifier with loss minimized design," EuMC 1998, vol. 1, pp. 144-149
Mizoe, J., T. Matsumura, K. Unosawa, Y. Akiba,, K. Nagai, H. Sato, T. Saryo, and T. Inoue, " A V-band GaAs MMIC chip set on a highly reliable WSi/Au refractory gate process," IEEE 1997 MTT-S IMS, pp. 248-250
Nishikawa, K., K. Kamogawa, K. Inoue, K. Onodera, M. Hirano, T. Tokumitsu, and I. Toyoda, "Millimeter-wave three-dimensional masterslice MMICs," IEEE 1998 MTT-S IMS, pp. 313-316
Ohashi, Y., T. Shimura, Y. Kawasaki, S. Aoki, H. Someta, T. Shimura, T. Hirose, and Y. Aoki, "76GHz flip-chip MMICs in through-hole packages," EuMC 1998, vol. 2, pp. 433-438
Takenaka, I., H. Takahashi, K. Asano, K. Ishikura, J. Morikawa, K. Sato, I. Takano, K. Hasegawa, K. Tokunaga, F. Emori, and M. Kuzuhara, "L/S-band 140W push-pull power AlGaAs/GaAs HFETs for digital cellular base stations," IEEE GaAs Symposium 1998, pp.81-84
Tanji, K., T. Kaneko, Y. Amamiya, T. Niwa, H. Shimawaki, S. Tanaka, and K. Wada, " A 38GHz low phase noise monolithic VCO for FM MOD using an AlGaAs/InGaAs HBT with p+/p regrown base contacts," EuMC 1998, vol. 1, pp. 47-51
Toyoda, I., and T. Ohira," High Integration technology for multifunctional MMICs: three-dimensional and wafer-scale design approaches," IEICE MWE 1996, pp. 245-250
ArF excimer lasers (193nm) have been studied intensively for the 1Gbit DRAM lithography and medical applications [Sekita et al., 1995]. Spectral narrowing up to 1-pm [Tada, et al., 1996] and long lifetime operation up to 100 million shots [Saito et al., 1996] were achieved.
High-order harmonics VUV lights were generated from rare gas (He, Ne) as nonlinear medium with Ti:sapphire laser [Miyazaki, et al., 1996][Kobayashi et al., 1996] and KrF excimer laser [Nagata et al., 1996]. Soft X-ray laser was also reported [Midorikawa et al., 1996].
High green power of 20W was generated with 14.2% optical-to-optical conversion efficiency from the intracavity-frequency-doubled Nd:YAG laser [Konno et al., 1997], and the intracavity compact SHG green laser was reported [Kitaoka et al., 1996]. UV light (213nm) was generated as a fifth harmonics of Nd:YAG with average power of 0.5W[Matsuda, et al., 1997], and VUV (193nm) light was obtained as a forth harmonics of Ti:sapphire laser [Kasamatsu et al., 1997].
Performances of tunable solid-state lasers have been improved. Broadband [Izawa et al., 1996] and electronically tuned Ti:sapphire laser [Wada et al., 1996] were reported. Tunable lasers are also useful to generate the fs short pulse. Extremely short pulse of 89 fs was generated from Cr:LiSAF laser [Ashida et al., 1997]. A single-mode Cr:LiSAF laser as an injection-seeder of the Ti:sapphire laser was developed [Maeda et al., 1996].
In 1997, NEDO(New Energy and Industrial Technology Development Organization) started the large-scale national project to realize the high power all solid-state lasers whose output powers will be 1kW with high beam quality or 10kW at the final goal in FY2001. TEM00 mode operation(M2<1.1) with high power of 208W was achieved[Hirano et al., 1998] under this project.
Novel lasers with new laser crystals and pumping configurations have been investigated to realize the higher power and new wavelength. Laser diode pumped zigzag slab Nd:YAG MOPA (Master Oscillator Power Amplifier) system generated 1.26J/pulse at the repetition rate of 200Hz [Tei et al., 1996]. High energy extraction efficiency of 73% was achieved with the eight-pass zig-zag slab laser amplifier [Kiriyama et al., 1998]. Yb lasers with high quantum efficiency due to quasi-three levels were studied [Taira et al., 1997][Kasamatsu et al., 1998]. All-solid-state Ce:LiSAF master oscillator power amplifier (MOPA) system generated UV short pulse[Sarukura et al., 1996]. Simultaneous cascade oscillation in the 3mm and 2mm bands with Ho3+ doped fiber laser was demonstrated [Sumiyoshi et al., 1997].
Aoshima, S., H. Itoh, Y.Tsuchiya," Compact geometry for diode-pumped Cr:LiSAF femtosecond laser," IEEE Journal of Selected Topics in Quantum Electronics, vol.3, pp. 95-99
Izawa, T., S.Matsui, M.Maeda, N.Yamamura, R.Uchimura, T.Yakuoh, N.Sarukura, L.Zhenlin, S.Izumida, Y.Segawa , "Broad-band tunable, compact, low-threshold, Ti:sapphire laser using a single set of extremely broad-band optics," CLEO '96, Summaries of Papers Presented at the Conference on Lasers and Electro-Optics, vol.9, 1996 Technical Digest Series. pp. 143-144
Kasamatsu, T., M. Tsunekane, H. Sekita, Y. Morishige, S. Kishida, " 1 pm spectrally narrowed ArF excimer laser injection locked by fourth harmonic seed source of 773.6nm Ti:sapphire laser," Applied Physics Letters, vol.67, pp. 3396-3398
Kasamatsu, T., H.Sekita, Y. Kuwano ,"Temperature-optimized operation of 970-nm diode-pumped Yb:YAG and Yb:LuAG lasers," OSA Trends in Optics and Photonics Series. vol.19, Advanced Solid State Lasers, pp. 125-128
Kiriyama, H., N.Nishida, M. Yamanaka, Y. Izawa, T. Yamanaka, S. Nakai, T. Kanzaki, H. Miyajima, M.Miyamoto, H. Kan, T. Hiruma , "Laser Diode-pumped eight pass Nd:YAG slab amplifier," Proceedings of the SPIE - The International Society for Optical Engineering, vol.3264, pp. 30-36
Kitaoka, Y., K.Mizuuchi, K.Yamamoto, M.Kato, Z.Wang-Long, T.Sasaki," Compact SHG green lasers," Proceedings of the SPIE - The International Society for Optical Engineering, vol.2682, pp. 70-77
Kobayashi, Y., O. Yoshihara, Y. Nabekawa, K. Kondo, S. Watanabe," QELS '96, Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference. vol.10, Technical Digest Series, p. 32
Konno, S., K.Yasui," Efficient 20W green-beam generation by intracavity-frequency-doubling of a Q-switched diode-pumped Nd:YAG laser," Proceedings of the SPIE - The International Society for Optical Engineering, vol.2986, pp. 108-112
Maeda, M. N.J.Vasa, T. Okada, M. Uchiumi, O. Uchino ," Tunable single-mode solid-state lasers with a new cavity configuration," Advances in Atmospheric Remote Sensing with Lidar. Selected Papers of the 18th International Laser Radar Conference (ILRC), pp. 443-446
Masuda, H., H.Kikuchi, H.Mori, K.Kaneko, M. Oka, S. Kubota, J. Alexander, "Single frequency 0.5W generation at 213nm from an injection-seeded, diode-pumped, high-repetition-rate,Q-switched Nd:YAG laser" OSA Trends in Optics and Photonics Series. vol.10, Advanced Solid State Lasers, pp. 2-6
Midorikawa, K., Y. Nagata, M. Obara, K. Toyoda," Optical-field-induced ionization X-ray laser studies using a preformed plasma," Proceedings of the SPIE - The International Society for Optical Engineering, vol. 2520, pp. 84-90
Miyazaki, K., H. Takada, M. Kakehata," High-intensity harmonic generation with a femtosecond Ti:sapphire laser," Progress in Crystal Growth and Characterization of Materials, vol. 33, pp. 233-236
Nagata, Y., K. Midorikawa, M. Obara, K. Toyoda ," High-order harmonic generation by subpicosecond KrF excimer laser pulses," Optics Letters, vol. 21, pp. 15-17
Saito, T., S. Ito, A. Tada ," Long lifetime operation of an ArF-excimer laser," Applied Physics B [Lasers and Optics], vol: B63, pp. 229-235
Sarukura, N., L. Zhenlin, S. Izumida, Y. Segawa, M.A. Dubinskii, V.V. Semashko, A.K. Naumov, S.L. Korableva, R.Y.Abdulsabirov ," Ultraviolet picosecond pulses from an all-solid-state Ce:LiSAF/Ce:LiCAF master oscillator and power amplifier system," CLEO '96, Summaries of Papers Presented at the Conference on Lasers and Electro-Optics, vol.9, 1996 Technical Digest Series. Conference Edition, pp. 112-113
Sekita, H., A. Tada, S. Ito ," 1 kHz high repetition rate, compact ArF excimer laser and its applications," LEOS '95. IEEE Lasers and Electro-Optics Society Annual Meeting. 8th Annual Meeting. Conference Proceedings, vol.1, pp. 302-303
Sumiyoshi, T., H. Sekita , "Dual wavelength (3mm and 2mm) CW cascade oscillation of a holmium-doped double-clad fiber laser," Proceedings of the IEEE Lasers and Electro-Optics Society 1997 Annual Meeting, pp.534-535
Tada, A., H.Sekita, S. Ito ," 1-pm spectrally narrowed compact ArF excimer laser for microlithography," CLEO '96, Summaries of Papers Presented at the Conference on Lasers and Electro-Optics, vol.9. 1996 Technical Digest Series. p. 374
Taira, T., J. Saikawa, M. Ohtaka, T. Kobayashi, R.L. Byer ," Modeling of end-pumped quasi-three-level lasers by using a M2 factor and CW operation of tunable Yb:YAG miniature lasers," OSA Trends in Optics and Photonics Series, vol.10 Advanced Solid State Lasers, pp. 189-191
Tei K., M. Kato, Y. Niwa, S. Harayama, Y. Maruyama, T. Matoba, T. Arisawa ," LD-pumped 0.62-J 105W Nd:YAG green laser," Proceedings of the SPIE - The International Society for Optical Engineering, vol.3265, pp.212-18
Wada, S., K.Akagawa, H.Tashiro , "Electronically tuned Ti:sapphire laser," Optics Letters, vol. 21, pp. 731-733
Wide-temperature-range (WTR) operation of long-wavelength Fabry-Perot and DFB lasers for use in access networks has been extensively researched by using the following approaches: 1) an InAlGaAs material system (To=122 K [Ohnoki et al., 1998], To=143 K [Anan et al., 1998]), 2) reverse-trapezoid ridge-waveguide structure (lasing up to 165 C [Aoki et al., 1997]), 3) InGaAs ternary substrates (lasing up to 210 C [Otsubo et al., 1998]), and 4) novel GaInNAs (To=127 K [Kondow et al., 1997]). The dominant mechanism that causes low To in InGaAsP/InP lasers was investigated from the viewpoint of the spontaneous emission efficiency [Higashi et al., 1997]. Moreover, the following milestones have been attained: 1) narrow-beam divergence lasers integrated with a spot-size converter for low-cost optical modules [Itaya et al., 1997; Kobayashi et al., 1997; Kasukawa et al., 1997; Aoki et al., 1997], 2) fabrication of a low-threshold monolithic laser array with a 1-mA range for optical interconnection (n-type modulation-doped MQW lasers [Nakahara et al., 1997], 3) Al-oxide confined inner stripe lasers [Iwai et al., 1998]), 4) complex-coupled WTR-DFB lasers [Kito et al., 1996], and 5) WTR-DFB lasers for CATV applications [Watanabe et al., 1997].
Short-wavelength lasers are very important as light sources for high-density information-processing systems. The first RT-pulsed operation [Nakamura et al., 1996A] and first RT-CW operation [Nakamura et al., 1996B] of a wide-gap InGaN-based laser was at a wavelength of 400 nm and reliability of more than 1,000 hours was achieved [Nakamura et al., 1998]. The shortest wavelength semiconductor laser (376 nm) was also demonstrated [Akasaki et al., 1996]. Moreover, the lifetime of wide-band-gap II-VI lasers has been improved to 400 hours [Kato et al., 1998].
High-power semiconductor laser technology has been demonstrated by applying a window-mirror structure to suppress the catastrophic optical damage or applying an Al-free material system. As a result, 650-nm laser diodes [Shima et al., 1997], 980-nm laser diodes [Sagawa et al., 1997; Fukagai et al., 1997; Yamamura et al., 1998], and 1.06-mm laser diodes [Asano et al., 1997] have been developed. Also, W-range optical power was achieved by using a decoupled confinement heterostructure in GaAs/AlGaAs laser diodes [Fujimoto et al., 1998].
Research on vertical-cavity-surface-emitting lasers (VCSELs) has produced stable polarization control by using (311)A substrates [Takahashi et al., 1997], 10-Gbit/s transmission [Hatori et al., 1998], GaAs-substrate-based GaInNAs [Kondow et al., 1997], and lasing emission by photopuming InGaN [Someya et al., 1998]. A low-threshold current in quantum-dot (Q-DOT) lasers was achieved by using a new formation of columnar-shaped dots [Mukai et al., 1998]. Semiconductor optical amplifier (SOA) gate modules with very low operating current and uniformity of 9.7+-0.5 mA to provide fiber-to-fiber gain of 0 dB have also developed [Kitamura et al., 1997].
High-speed 152-GHz uni-traveling-carrier photodiodes have been realized by using only electrons as active carrier [Ishibashi, 1998]. A low-dark current (0.27 nA) waveguide photodiodes with Fe-doped InP blocking layer have been reported [Aoyagi et al., 1997.]. Highly reliable superlattice avalanche photodiodes with a planer structure have been developed for 10 Gbit/s application [Watanabe et al., 1997]. A 0.95 W/A edge-illuminated refracting-facet photodiode has been developed for low-cost optical module applications [Fukano et al., 1997]. Highly-reliable waveguide photodiodes with 10,000-hours operation at 85C / 85% RH have been developed for low-cost plastic packages [Nakamura, 1998].
Akasaki, I., S. Sota, H. Sakai, T. Tanaka, M. Koike and H. Amano, "Shortest wavelength semiconductor laser diode," Electron.Lett., vol.32, p.1105
Anan, T., M. Yamada, K. Tokutome, and S. Sugou, "1.3-mm InAsP/InAlGaAs MQW lasers for high-temperature operation," SPIE, vol.3284, pp.172-180
Aoki, M., M. Komori, T. Tsuchiya, H. Sato, K. Nakahara, and K. Uomi, "InP-based reversed-mesa ridge-waveguide structure for high-performance long-wavelength laser diodes," IEEE J. Selected Topics in Quantum Electron., vol.3, pp.672-683
Aoyagi, T., E. Ishimura, S. Funaba, D. Suzuki, T. Kimura, T. Sogo, and M. Aiga, "Subnanoamperes dark current and high-efficiency waveguide photodiodes with 32-GHz bandwidth buried with Fe-doped Indium Phosphide," OFC'97, TuI3, Feb.
Arahira, S., Y. Matsui, and Y. Ogawa, "Mode-locking at very high repetition rates more than Terahertz in passively mode locked distributed-bragg-reflector laser diodes," IEEE J. Quantum Electron., vol.32, pp.1211-1218
Asano, H., M. Wada, T. Fukunaga, and T. Hayakawa, "Temperature insensitive characteristics of 1.06mm strain-compensated single quantum well laser diodes (SQW-LDs)," 16th IEEE International Semicond. Laser Conf., Sept. Paper TuA3
Fujimoto, T., Y. Yamada, Y. Oeda, A. Okubo, Y. Yamada and K. Muro, "830-nm high-power, low-noise MQW laser with power over 1 W," SPIE, pp.3285-16
Fukagai, K., H. Chida, T. Arakida, T. Miyazaki, and S. Ishikawa, "Highly controlled fundamental lateral-mode operation of 980 nm lasers fabricated by a combination process of dry and selective wet etching," OECC'97, Seoul, 10C4-4.
Fukano, H., A. Kozen, K. Kato, and O. Nakajima, "High-responsivity and low-operation-voltage edge-illuminated refracting-facet photodiodes with large alignment tolerance for single-mode fiber, " IEEE J. Lightwave Technol., vol.15, pp.894-899
Hatori, N., A. Mizutani, N. Nishiyama, A. Matsutani, T. Sakaguchi, F. Motomura, F. Koyama and K. Iga, "An over 10Gbits/s transmission experiment using p-type delta-doped InGaAs/GaAs quantum-well vertical cavity surface emitting laser," IEEE Photon. Tech. Lett., vol.10, pp.194-196
Higashi, T., T. Yamamoto, S. Ogita, and M. Kobayashi, "Experimental analysis of characteristic in quantum-well semiconductor lasers," IEEE J. Select. Topics Quantum Electron., vol.3, pp.513-521
Ishibashi, T., "High-speed high-saturation power InP/InGaAs uni-traveling-carrier photodiodes," OECC'98, 15B3-1, pp.352-353
Ishizaka, M., M.Yamaguchi, Y.Sakata, Y.Inomoto, J.Shimizu, and K.Komatsu, "Distributed-feedback laser diode (DFB-LD) with monolithically integrated electroabsorption 2.5Gbps-700km transmission," IEEE Photonics Technol. Lett., vol. 9, pp. 1406-1408
Itaya, Y., Y. Tohmori, and H. Toba, "Spot-size converter integrated laser diodes (SS-LD's)," J. Selected Topics in Quantum Electron., vol.3, pp.968-974
Iwai, N., T. Mukaihara, H. Shimizu, N. Yamanaka, K. Kumada, and A. Kasukawa, "Low threshold current 1.3mm InAsP QW ACIS lasers," Electron.Lett., vol.34, pp.890-891
Kasukawa, A., K. Nishikata, N. Yamanaka, S. Arakawa, N. Iwai, T. Mukaihara, and T. Matsuda, "Structural dependence of 1.3-mm narrow-beam lasers fabricated by selective MOCVD growth," J. Selected Topics in Quantum Electron., vol.3, pp.1413-1420
Kato, E, H. Noguchi, M. Nagai, H. Okuyama, S. Kijima and A. Ishibashi, "Significant progress in II-VI blue-green laser diodes," Electron. Lett., vol.34, pp.282-283
Kitamura, S., H. Hatakeya, T. Kato, N. Kimura, M. Yamaguch and K. Komatsu, "Very low operating current SOA-gate modules for optical matrix switches," OAA'97, paper TuC3
Kito, M., S. Nakamura, N. Otsuka, M. Ishino, and Y. Matsui, "New structure of 1.3 mm strained-layer multi-quantum well complex-coupled distributed feedback lasers," Jpn. J. Appl. Phys., vol.35, pp.1375-1377
Kobayashi, H., T. Watanabe, T. Yamamoto, T. Takeuchi, S. Ogita, and M. Kobayashi, "Highly reliable tapered thickness waveguide lasers," 2nd OECC'97, 10C1-4, pp.442-443
Kondow, M., T. Kitatani, S. Nakatsuka, M. C. Larson, K. Nakahara, Y. Yazawa, M. Okai, K. Uomi, GaInNAs, "A novel material for long-wavelength semiconductor lasers," IEEE J. Selected Topics in Quantum Electron., vol.3, pp.719-730
Koutoku, M., H. Sanjoh, S. Oku, Y. Kadota, Y. Yoshikuni, and Y. Shibata, "InP-based 64-channel arrayed waveguide grating with 50 GHz channel spacing and up to -20 dB crosstalk," Electron Lett., vol.33, pp.1786-1787
Kudo, K., H. Yamazaki, T. Sasaki, and M. Yamaguchi, "Wide-wavelength range detuning-adjusted DFB-LD's of different wavelengths fabricated on a wafer," IEEE Photon. Technol. Lett., vol.9, pp.1313-1315
Miyazaki, Y, E. Ishimura, K. Takagi, K. Kuramoto, H. Tada, K. Matsumoto, T. Takiguchi, T. Kadowaki, M. Fujiwara, A. Takemoto, and H. Higuchi, "Ultra-low chirp EAM-DFB-LD for 2.5Gbps-700km penalty-free transmission," 16th IEEE International Semicond. Laser Conf., TuD3, Oct
Mukai, K., Y. Nakata, H. Shoji, M. Sugawara, K. Ohtsubo, N. Yokoyama, and H. Ishikawa, "Lasing with low threshold current and high output power from columnar-shaped InAs/GaAs quantum dots," Electron. Lett., vol.34, pp.1588-1590
Muroya, Y., K. Sato, T. Okuda, T. Nakamura, H. Yamada, and T. Torikai, "Precisely wavelength-controlled corrugation for DFB laser diodes delineated by weighted-dose electron beam lithography, " IEICE Trans. Electron, vol.E81-C, pp.1225-1231
Nakahara, K., K. Uomi, T. Tsuchiya, A. Niwa, T. Haga, and T. Taniwatari, "1.3-mm InGaAsP-InP n-Type modulation-doped strained multiquantum-well lasers," IEEE J. Selected Topics in Quantum Electron., vol.3, pp.166-172
Nakamura, H., "Highly reliable operation of InGaAlAs mesa-waveguide photodiodes in humid ambient", Mat. Res. Soc. Symp., vol.531, pp.317-325
Nakamura, S., M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku and Y. Sugimoto, "InGaN-based multi-quantum-well-structure laser diodes," Jpn. J. Appl. Phys. Vol.35, pp.L74-L77
Nakamura, S., M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, Y. Sugimoto, and H. Kiyoku, "Room-temperature continuous-wave operation of InGaN multi-quantum-well structure laser diodes," Appl. Phys. Lett. vol.69, pp.4056-4058
Nakamura, S., M. Senoh, S. Nagahama, N. Iwasa, T. Yamada, T. Matsushita, H. Kiyoku, Y. Sugimoto, T. Kozaki, H. Umemoto, M. Sano, and K. Chocho, "InGaN/GaN/AlGaN-based laser diodes with modulation-doped strained-layer superlattices grown on an epitaxially laterally overgrown GaN substrate," Appl. Phys. Lett. vol.72, 2, pp.211-213
Ohnoki, N., G. Okazaki, F. Koyama and K. Iga, "Record high characteristic temperature (To=122K) in 1.55mm AlGaInAs lasers with AlAs/AlInAs multiple quantum barrier," IEEE 16th International Semiconductor Laser Conference, PD-9.
Otsubo, K., H. Shoji, T. Kusunoki, T. Suzuki, T. Uchida, Y. Nishijima, K. Nakajima, and H. Ishikawa, "Long-wavelength strained quantum-well lasers oscillating up to 210 C on InGaAs ternary substrates," IEEE Photon. Technol. Lett., vol.10, pp.1073-1075
Sagawa, M., K. Hiramoto, T. Toyonaka, T. Kikawa, S. Fujisaki, and K. Uomi, "Highly reliable and stable-lateral-mode operation of high-power 0.98-mm InGaAs-InGaAsP lasers with an exponential-shaped flared stripe," IEEE J. Selected Topics in Quantum Electron., vol.3, pp.666-671
Shima, A., H. Tada, K. Ono, M. Fujiwara, T. Utakouji, T. Kimura, M. Takemi, and H. Higuchi, "Highly reliable 60 C 50-mW operation of 650-nm band window-mirror laser diodes," IEEE Photon. Technol. Lett., vol.9, pp.413-415
Someya, T., K. Tachibana, Y. Arakawa, J. Lee, and T. Kamiya, "Lasing oscillation in InGaN vertical cavity surface emitting lasers," IEEEE 16th International Semiconductor Laser Conference, PD-1
Sudoh, T., Y. Nakano, and K. Tada, "Wavelength trimming by external light irradiation post fabrication lasing wavelength adjustment for multiple-wavelength distributed-feedback laser arrays," IEEE Journal of Selected Topics in Quantum Electronics, vol.3, pp.577-583
Takahashi, M., N. Egami, T. Mukaihara, F. Koyama, and K. Iga, "Lasing characteristics of GaAs(311)A substrate based InGaAs/GaAs vertical-cavity surface-emitting lasers," IEEE J. Select. Top. Quantum. Electron, vol.3, pp.372-378
Takeuchi, H., K. Tsuzuki, K. Sato, M. Yamamoto, Y. Itaya, A. Sano, M. Yoneyama, and T. Otsuji, "NRZ operation at 40 Gb/s of a compact module containing an MQW electroabsorption modulator integrated with a DFB laser," IEEE Photonics Technology Lett., vol.9, pp.572-574
Tsuzuki, K., H. Takeuchi, S. Oku, H. Tanobe, Y. Kadota, F. Kano, H. Ishii, and M. Yamamoto, "InP-based monolithic optical frequency discriminator module for WDM systems," OECC'98, 16B4-5, pp.480-481
Watanabe, H., T. Aoyagi, K. Shibata, T. Takiguchi, S. Kakimoto, and H. Higuchi, "1.3-mm uncooled DFB lasers with low distortion for CATV application," IEEE J. Selected Topics in Quantum Electron., vol.3, pp.659-665
Watanabe, I., T. Nakata, M. Tsuji, K. Makita, and K. Taguchi, "High-reliability, low-dark-current, and wide-dynamic-range planar-structure superlatice APDs for 10 Gb/s optical receivers," ECOC'97, TH2D, pp.93-96
Yamada, K., K. Nakamura, and H. Horikawa, "Design of double-pass electroabsorption modulators with low-voltage, high-speed properties for 40 Gb/s modulation," IEEE J. Lightwave Technol., vol.15, pp.2287-2292
Yamamura, S., K. Shigihara, K. Kawasaki, Y. Nagai, M. Miyashita, A. Takemoto, and H. Higuchi, "Highly reliable 0.98mm laser diodes with a window structure fabricated by Si-ion implantation," OECC'98, 16D2-4, Jul.
Optical analog transmission technology for CATV applications has shown much progress. In order to improve the yield of DFB laser a novel partially corrugated design has been developed [Okuda et al., 1996] and for upstream communication low cost coaxial DFB laser module was developed [Nakabayashi et al., 1997].
Photonic switching technology has been greatly progressed to realize optical communication networks. 10 Gb/s photonic cell switching was demonstrated by using 4 x 4 hybrid optical matrix switch module on silica-based planar waveguide platform [Kato et al., 1998]. Semiconductor arrayed waveguide gratings were also reported and polarization-independent InP arrayed waveguide filter was realized [Kohtoku et al., 1997]. VCSELs for optical interconnect have also advanced and 10Gbps transmission experiment using InGaAs-GaAs quantum well VCSEL was reported [Hattori et al., 1998].
Aisawa S., T. Sakamoto, M. Fukui, J. Kani, M. Jinno, and K. Oguchi , "Ultra-wide band, long distance WDM transmission demonstration: 1 Tb/s (50 x 20 Gb/s), 600 km transmission using 1550 and 1580 nm wavelength bands," OFC'98 Technical Digest, PD11
Edagawa N., I. Morita, M. Suzuki, S. Yamamoto, K. Tanaka, and S. Akiba , "Long distance soliton WDM transmission using a dispersion-flattened fiber," OFC'97, Technical Digest, PD19
Hattori, Nobuaki, A. Mizutani, N. Nishiyama, A. Matsutani, T. Sakaguchi, F. Motomura, F. Koyama, and K. Iga , "An over 10-Gb/s transmission experiment using a p-type delta-doped InGaAs-GaAs quantum-well vertical-cavity surface-emitting laser," IEEE Photon. Tech. Lett., vol.10, pp.194-196
Kato, T., J. Sasaki, T. Shimoda, H. Hatakeyama, T. Tamanuki, M. Yamaguchi, M. Kitamura, and M. Ito , "10 Gb/s photonic cell switching with hybrid 4 x 4 optical matrix switch module on silica based planar waveguide platform," OFC'98 Technical Digest, PD3
Kohtoku M., H. Sanjo, S. Oku, Y. Kadota, and Y. Yoshikuni , "Polarization-independent InP arrayed waveguide grating filter using deep ridge waveguide structure," CLEO/Pacific Rim '97, Technical Digest, FN4
Nakabayashi T., I. Keiko, A. Miki, M. Murata, H. Kobayashi, M. Yoshimura, K. Yoshida, G. Sasaki and T. Katsuyama , "Uncooled DFB laser modules operating with low distortion over a wide temperature range for a return path of CATV networks," OFC'97 Technical Digest, ThR3
Nakazawa M., K. Suzuki, H. Kubota, A. Sahara, and E. Yamada , "100 Gb/s WDM (20 Gb/s x 5 channels) soliton transmission over 10,000km using in-line synchronous modulation and optical filtering," OFC'97, Technical Digest, PD21
Nakazawa, M., E. Yoshida, T. Yamamoto, E. Yamada, and A. Sahara , "TDM single channel 640 Gb/s transmission experiment over 60km using a 400 fs pulse train and a walk-off free, dispersion-flattened nonlinear optical loop mirror," OFC'98 Technical Digest, PD14
Okuda T., H. Yamada, Y. Sasaki, T. Torikai, and T. Uji , "Wide-power range, low- distortion 1.3mm partially corrugated waveguide laser diodes for broadcast CATV networks", ECOC'96, Proceedings, MoC.3.5
Onaka, H., H. Miyata, G. Ishikawa, K. Otsuka, H. Ooi, Y. Kai, S. Kinoshita, M. Seino, H. Nishimoto, and T. Chikama , "1.1 Tb/s WDM transmission over a 150km 1.3mm zero-dispersion single-mode fiber," OFC'96 Technical Digest, PD19
Yano, Y., T. Ono, K. Fukuchi, T. Ito, H. Yamazaki, M. Yamaguchi, and K. Emura , "2.6 Terabit/s WDM transmission experiment using optical duobinary coding," ECOC'96, Proceedings, ThB.3.1
Application of high-Tc superconductors to the digital electronics depends on the Josephson junction quality which remains to be improved. The critical current uniformity in the high-Tc Josephson junctions was improved by employing a new substrate material of lanthanum-strontium-aluminium tantalate combined with the in situ etching process. With this method, a value of as low as 16% was attained for the one-sigma critical current spread for 48 junctions [Sato 1998].
Another important area of the cryoelectronics is the microwave application of high-Tc superconcuctors. A Superconducting filter subsystem was developed aiming for the use in mobile telecommunication systems [Ueno 1998]. The subsystem was equipped with an 11-pole microstripline band-pass filter made of an yttrium-barium cuprate high-Tc superconducting epitaxial thin film together with a low-noise preamplifier and a Starling cryocooler. It operated at 70 K with an insertion loss of less than 0.1 dB and a noise figure of 0.5 dB.
A prototype power transmission microwave bandpass filter was fabricated from a high-Tc superconductor thin film with an aim for the use in the mobile power transmission front end of the base stations [Setsune 1998]. The filter provided values of less than 0.2 dB for the insertion loss below an input power of 30 dBm at a center frequency of 5.1 GHz [Enokihara 1996]. The maximum input power was 41.2 dBm (approximately 15 W).
Enokihara, A. and K. Setsune , "High-Tc superconducting planar filter for power handling capability," IEICE Trans. Electron., vol.E79-C, 9, p.1228
Satoh, T, M. Hidaka, and S. Tahara , "Multilayer edge junctions for high temperature superconducting circuits," 1998 Applied Superconductivity Conference, Extended Abstracts, p.78
Setsune, K., A. Enokihara, and K. Mizuno , "High-Tc superconducting filters for power signal transmission on communication base station," IEICE Trans. Electron. vol.E81-C, 10, pp.1578-1583
Tahara, S. and S. Yorozu , "A superconducting ring-pipelined network system," IEEE Trans. Appl. Supercond. vol.5, pp.3164-3167
Ueno, Y., K. Saito, N. Sakakibara, M. Okazaki, and M. Aoki , "High-temperature superconducting microstrip line filter for mobile telecommunication," IEICE Trans. Electron. vol.E81-C, 10, pp.1573-1577
Yorozu, S, Y. Hashimoto, and S. Tahara , "System demonstration of superconducting communication system," 1998 Applied Superconductivity Conference, Extended Abstracts, p.69