Papers - ARAI Masakazu
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Kondo T., Arai M., Matsutani A., Miyamoto T., Koyama F.
Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS 2 501 - 502 2003.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS
A highly strained GaInAs/GaAs VCSEL emitting at 1.13 μm was demonstrated. As such, the threshold current was below 1 mA. A maximum single mode output power of over 2mW was achieved. Such reuslts indicated that a highly strained 1.1-1.2μm range GaInas VCSEL can be useful for high capacity metro-area networks.
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Amano T., Koyama F., Arai M., Matsutani A.
Japanese Journal of Applied Physics, Part 2: Letters 42 ( 11 B ) 2003.11
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics, Part 2: Letters
We present the design of novel micromachined vertical-cavity light emitters/lasers with a thermal strain control layer for temperature-insensitive operations. The temperature dependence of a resonant wavelength can be freely controlled in a micromachined cantilever structure. We demonstrated a micromachined resonant-cavity light emitter with a small temperature dependence of the emission wavelength. The temperature dependence was as small as +0.015 nm/K, which is five times smaller than that of conventional single-mode lasers.
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Arai M., Kondo T., Onomura A., Matsutani A., Miyamoto T., Koyama F.
IEEE Journal on Selected Topics in Quantum Electronics 9 ( 5 ) 1367 - 1373 2003.9
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：IEEE Journal on Selected Topics in Quantum Electronics
The wavelength engineering of vertical cavity surface emitting lasers (VCSEL) on a nonplanar substrate enables us to realize a multiwavelength VCSEL array. We are able to control the wavelength of both a cavity resonance and the gain peak of an active region, depending on patterned shapes. A main limiting factor in expanding the wavelength span in arrays is the offset between the gain peak and the resonant wavelength. In order to overcome this offset, we optimized a gain-cavity detuning to extend the wavelength span. A wavelength span of over 100 nm was obtained from a fabricated 12-channel array. The output power is over 1 mW, and threshold current is 0.65 ± 0.2 mA. We carried out the compensation of the threshold current-density variation by the precise control of oxide apertures in each element. In addition, we proposed a growth-pressure control in epitaxial growth on a patterned substrate for further extension of the lasing wavelength span. We demonstrated a 0.96-1.16-μm multiple-wavelength VCSEL array with highly strained GaInAs-GaAs QWs exhibiting a record wavelength span of 192 nm. These technologies would enable low-cost wideband wavelength division multiplexing data links.
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Densely integrated multiple-wavelength vertical-cavity surface-emitting laser array
Onomura A., Arai M., Kondo T., Matsutani A., Miyamoto T., Koyama F.
Japanese Journal of Applied Physics, Part 2: Letters 42 ( 5 B ) 2003.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics, Part 2: Letters
We demonstrated a densely integrated multiple-wavelength GaInAs/GaAs vertical-cavity surface-emitting laser (VCSEL) array using non planar metal-organic chemical vapor deposition (MOCVD). The fabricated 1-mm-long array consists of 20-channel VCSELs and the pitch between each channel is as small as 50 μm. The lasing wavelength of each channel was precisely designed based on the relationship between the lasing wavelength and the pattern width. The wavelength spacing is within 1 nm. All VCSELs exhibited single-mode operation, an output power of over 1.2 mW and a threshold current of 0.52 ± 0.1 mA.
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Design and fabrication of GaAs-GaAlAs micromachined tunable filter with thermal strain control
Amano T., Koyama F., Hino T., Arai M., Mastutani A.
Journal of Lightwave Technology 21 ( 3 ) 596 - 601 2003.3
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Journal of Lightwave Technology
In this paper, we present the design and fabrication of a novel GaAlAs-GaAs micromachined vertical Cavity filter with a thermal strain control layer for wide wavelength tuning. The integration of a thermal strain control layer and heating element enables wavelength tuning induced by heating. The proposed tunable filter under thermal tuning operation provides Us large tuning range over conventional micromachined tunable filters using electrostatic force. The calculated result shows a possibility of large continuous tuning range of over 100 nm. We fabricated a micromachined GaAlAs-GaAs vertical cavity filter with a strain control layer. The temperature dependence of the filter can be freely controlled either with temperature insensitive operation or with an enhanced temperature dependence, which depends on the thickness of the thermal strain control layer. We demonstrate a thermal wavelength tuning of 53 nm with a low tuning voltage of 6.1 V for the first time.
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Micromachined resonant cavity light emitter with low temperature dependence of emission wavelength
Amano T., Koyama F., Arai M., Mastutani A.
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest 1 2003
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest
We present the design and the fabrication of novel micromachined vertical-cavity light emitters/lasers with a thermal strain control layer for temperature insensitive operations. The temperature dependence of a resonant wavelength can be freely controlled in a michromachined cantilever structure. We demonstrated a micromachined resonant cavity light emitter with a low temperature dependence of an emission wavelength. The temperature dependence was as small as + 0.015 nm/K.
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Arai M., Kondo T., Matsutani A., Miyamoto T., Koyama F.
Device Research Conference - Conference Digest, DRC 2003-January 153 - 154 2003
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Device Research Conference - Conference Digest, DRC
© 2003 IEEE. In this paper, we propose a growth pressure control during MOCVD growth of VCSEL wafers on a patterned substrate to avoid the mismatch between a grain peak and resonant mode. We demonstrate a multiple wavelength GaInAs/GaAs VCSEL array emitting in a new wavelength window of 0.9-1.2 μm, exhibiting a record wavelength span of 192 nm.
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Multi-oxide layer vertical-cavity surface-emitting lasers with improved modulation bandwidth
Azuchi M., Jikutani N., Arai M., Kondo T., Koyama F.
Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest 1 2003
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest
We demonstrated VCSELs with multi-oxide layers (MOX) to reduce parasitic capacitance for high speed modulation beyond 10 GHz. We achieved a small signal modulation bandwidth of 11 GHz while that of a conventional single oxide layer VCSEL is 7 GHz.
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1.23μm long wavelength highly strained GaInAs/GaAs quantum well laser
Kondo T., Arai M., Onomura A., Miyamoto T., Koyama F.
Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS 2 618 - 619 2002.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS
An attempt was made to extend the emission wavelength of highly strained GaInAs/GaAs SQW over 1.2 μm under growing at a high growth rate of 9 μm/h. The longest Pl peak wavelength of 1.27 μm was obtained. A highly strained GaInAs/GaAs SQW stripe-laser was also demonstrated. The lasing wavelength reached 1.23 μm with a threshold current density of 1.7 kA/cm2.
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Dynamic response of thermally tunable micromachined optical filter with low tuning voltage
Amano T., Hino T., Koyama F., Arai M., Matsutani A.
Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS 2 829 - 830 2002.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS
An overview is given of some tuning characteristics of a GaAlAs/GaAs micromachined tunable filter with integrating a thermal strain control layer and heating element on a top surface. The design of micromachined filters for wide tuning range and for fast wavelength tuning is presented. Experimentally, the fast tuning response with rise time and fall time of below 100 μs is demonstrated.
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Densely integrated multiple-wavelength vertical cavity surface emitting laser array
Onomura A., Arai M., Kondo T., Matsutani A., Miyamoto T., Koyama F.
Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS 2 689 - 690 2002.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS
The operation of a 20-ch densely integrated multiple wavelengths VCSEL array on a patterned GaAs substrate was followed. All VCSELs exhibited single mode operation, and output power of over 1.2mW, and the threshold current of 0.52±0.1 mA. The result shows a possibility of large scale multiple-wavelength sources densely packed in a small chip.
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1200 nm highly strained GaInAs/GaAs surface emitting lasers
Koyama F., Miyamoto T., Arai M., Kondo T.
Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS 1 271 - 272 2002.12
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS
Low threshold current density operations of highly strained GaInAs/GaAs QW lasers emitting at nearly 1.2 μm wavelength was demonstrated. It was realized that 1.2 μm uncooled vertical cavity surface emitting lasers (VCSELs) and multiple-wavelength arrays including their use in single mode fiber data transmission. This paper reviews the results on 1.2 μm GaInAs/GaAs VCSELs including their temperature lasing characteristics and wavelength engineering on patterned substrates.
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Singlemode fibre transmission using 1.2 μm band GaInAs/GaAs surface emitting laser
Kondo T., Arai M., Azuchi M., Uchida T., Matsutani A., Miyamoto T., Koyama F.
Electronics Letters 38 ( 16 ) 901 - 903 2002.8
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electronics Letters
Singlemode fibre (SMF) transmission using a 1.2 μm band GaInAs/GaAs vertical cavity surface emitting laser (VCSEL) is demonstrated. It was observed that the short optical pulse with a pulse width of 60 ps was compressed to 50 ps after transmitting in a 10 km-long SMF due to the frequency chirp of a VCSEL and the negative fibre dispersion at 1.2 μm. This result indicates that this new wavelength window would enable high bit rate data transmission beyond 10 Gbit/s without chirp penalties.
DOI： 10.1049/el:20020598
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GaAlAs/GaAs micromachined thermally tunable vertical cavity filter with low tuning voltage
Amano T., Koyama F., Arai M.
Electronics Letters 38 ( 14 ) 738 - 740 2002.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electronics Letters
A GaAlAs/GaAs micromachined thermally tunable vertical cavity filter with a low tuning voltage is proposed and its fabrication described. The integration of a thermal strain control layer and heating element enables wavelength tuning induced by heating. Wavelength tuning of 23.2 nm with a low tuning voltage of 4.7 V is demonstrated experimentally.
DOI： 10.1049/el:20020490
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Arai M., Kondo T., Matsutani A., Miyamoto T., Koyama F.
IEEE Journal on Selected Topics in Quantum Electronics 8 ( 4 ) 811 - 816 2002.7
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：IEEE Journal on Selected Topics in Quantum Electronics
We carried out the growth of highly strained GaInAs-GaAs quantum wells (QWs) on a patterned substrate for extending an emission wavelength on a GaAs substrate. We examined the shift of photoluminescence wavelength of the QWs and show a large wavelength shift due to the spatial modulation in well thickness and indium composition. We demonstrated a single-mode multiple-wavelength vertical-cavity surface-emitting laser (VCSEL) array on a patterned GaAs substrate covering a new wavelength window of 1.1-1.2 μm. By optimizing a pattern shape, we achieved multiple-wavelength operation with widely and precisely controlled lasing wavelengths. The maximum lasing span is as large as 77 nm. We carried out a data transmission experiment through a 5-km single-mode fiber with 2.5 Gb/s/channel. The total throughput reaches 10 Gb/s. The VCSEL-based wavelength-division-multiplexing (WDM) source would be a good candidate for WDM-LAN beyond 10 Gb/s.
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Kondo T., Arai M., Azuchi M., Uchida T., Matsutani A., Miyamoto T., Koyama F.
Japanese Journal of Applied Physics, Part 2: Letters 41 ( 5 B ) 2002.5
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics, Part 2: Letters
We demonstrate highly strained GaInAs/GaAs quantum well (QW) vertical cavity surface emitting lasers (VCSELs) emitting at 1.16 μm with a low threshold current density and high efficiency in the 1.2-μm-wavelength band. The VCSEL structure was monolithically grown on a (100) n-type GaAs substrate by low-pressure metalorganic vapor phase epitaxy (MOVPE). The threshold current is 3 mA for a 10 × 10 μm2 oxide aperture device, corresponding to a threshold current density of 3 kA/cm2. The maximum output power ismore than 2 mW. The maximum CW operating temperature is 85°C and the threshold current is almost constant in temperature range of 25-75°C.
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Single high-order transverse mode surface emitting laser with micromachined surface relief
Shinada S., Koyama F., Nishiyama N., Arai M.
IEICE Transactions on Electronics E85-C ( 4 ) 995 - 1000 2002.4
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：IEICE Transactions on Electronics
We demonstrate a single high-order transverse mode surface emitting laser (VCSEL) with narrow trenches formed on a top surface. The design and the fabrication of a single high-order mode 850 nm GaAs VCSEL with micromachined surface relief are presented. Stable single-mode operation with a side-mode suppression ratio of over 40 dB was obtained in an entire measured current range. We obtained the maximum single mode power of over 3.5 mW and a record low series resistance of below 50 Ω. In addition, a single-lobe far field pattern is demonstrated even under high-order transverse mode operation by loading phase-shift on the top surface. A coupling efficiency with optical fibers is dramatically improved.
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1.4 μm GaInNAs/GaAs quantum well laser grown by chemical beam epitaxy
Ikenaga Y., Miyamoto T., Makino S., Kageyama T., Arai M., Koyama F., Iga K.
Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 41 ( 2 A ) 664 - 665 2002.2
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
The room-temperature pulsed operation of GaInNAs/GaAs double quantum well (DQW) lasers emitting at 1.4 μm grown by chemical beam epitaxy (CBE) with increased nitrogen composition was demonstrated. An increased threshold current density was observed with respect to a 1.3 μm GaInNAs laser due to degradation of the crystal quality. The results showed that the long-wavelength lasers beyond 1.3 μm can be obtained by improving the crystal quality.
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Optical near field by vertical cavity surface emitting laser
Shinada S., Koyama F., Nishiyama N., Arai M., Matsutani A., Goto K., Iga K.
Electronics and Communications in Japan, Part II: Electronics (English translation of Denshi Tsushin Gakkai Ronbunshi) 85 ( 2 ) 43 - 53 2002.2
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Electronics and Communications in Japan, Part II: Electronics (English translation of Denshi Tsushin Gakkai Ronbunshi)
Our research examines the generation of an optical near field by a vertical cavity surface emitting laser (VCSEL), which can readily be formed into a two-dimensional array, and the possible application to optical recording capable of high-speed data transfers due to the higher density and parallel processing achieved when the optical near field is used as the optical head. We propose a VCSEL with metal micro-aperture for generating the optical near field. Then we demonstrate the ability to create a micro spot size of 100 nm or smaller based on this structure from analysis of the intensity distribution of the micro-aperture by the two-dimensional finite element method. We also form a micro-aperture by using a focused ion beam in a GaAs/AlGaAs VCSEL with an 850-nm wavelength and perform initial evaluations. In these evaluations, we obtained an emitted power density of 0.12 mW/μm2 from a 400-nm square micro-aperture. Furthermore, we observed the light from a 100-nm square aperture in near field observations and verified the generation of an optical near field by this structure.
DOI： 10.1002/ecjb.1092
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Arai M., Kondo T., Azuchi M., Uchida T., Matsutani A., Miyamoto T., Koyama F.
Conference Proceedings - International Conference on Indium Phosphide and Related Materials 303 - 306 2002
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Conference Proceedings - International Conference on Indium Phosphide and Related Materials
We demonstrated a single-mode multiple wavelength VCSEL array with highly strained GaInAs/GaAs QWs on a patterned GaAs substrate in a new wavelength band of 1.1-1.2 μm. The emission wavelength of a 4-channel array ranges from 1137 nm to 1144 nm. We carried out data transmission experiment through a 5 km single mode fiber with 2.5 Gbps/channel. The total throughput reaches at 10 Gbps. This novel WDM source would be a good candidate for WDM-LAN beyond 10 Gbps. In addition, we show a potential extension of the wavelength span for multiple wavelength VCSEL arrays by optimizing the pattern shape of a substrate.