The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Hirohito Yamada - One of the best experts on this subject based on the ideXlab platform.
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narrow Spectral Linewidth silicon photonic wavelength tunable laser diode for digital coherent communication system
IEEE Journal of Selected Topics in Quantum Electronics, 2016Co-Authors: Tomohiro Kita, Rui Tang, Hirohito YamadaAbstract:We demonstrated wavelength tunable laser diodes with Si-wire waveguide ring resonators as an external optical cavity. The footprint of the optical cavity including the semiconductor optical amplifier is as small as 0.8 mm × 0.6 mm which is less 1/10 of those made of silicon oxinitride material. Wavelength tuning range of approximately 55 nm was demonstrated, which covers entire L-band of the optical communication wavelength system. Furthermore, a Spectral Linewidth narrower than 100 kHz was obtained by optimizing the design of the external optical cavity. The optical nonlinearity of silicon is described and the influence on laser oscillation is also discussed.
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narrow Spectral Linewidth silicon photonic wavelength tunable laser with highly asymmetric mach zehnder interferometer
Optics Letters, 2015Co-Authors: Rui Tang, Tomohiro Kita, Hirohito YamadaAbstract:We propose a narrow-Spectral-Linewidth silicon photonic wavelength-tunable laser with a novel external wavelength-tunable filter, which consists of two silicon ring resonators with different circumferences and a highly asymmetric Mach–Zehnder interferometer (MZI), the two optical paths of which have significantly different lengths. Calculations and experimental results indicated that the gain difference between longitudinal modes was increased by the highly asymmetric MZI. Consequently, a narrow Spectral Linewidth of 12 kHz and a stable single-mode oscillation were obtained.
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narrow Spectral Linewidth and high output power si photonic wavelength tunable laser diode
International Conference on Group IV Photonics, 2013Co-Authors: Tomohiro Kita, Keita Nemoto, Hirohito YamadaAbstract:We fabricated wavelength tunable laser diodes with Si photonic wire waveguide ring resonators as an external optical cavity. Less than 100 kHz narrow Spectral Linewidth was obtained with small footprint. Our wavelength tunable laser diode shows sufficient good performance for practical use in digital coherent optical transmission systems.
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narrow Spectral Linewidth wavelength tunable laser with si photonic wire waveguide ring resonators
International Conference on Group IV Photonics, 2012Co-Authors: Keita Nemoto, Tomohiro Kita, Hirohito YamadaAbstract:We fabricated wavelength tunable laser diodes with Si-wire waveguide ring resonators as an external optical cavity. Less than 100 kHz narrow Spectral Linewidth was obtained by optimizing design of the ring resonators. The wavelength tunable laser diodes with narrow Spectral Linewidth are suitable as light sources for digital coherent optical transmission systems.
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narrow Spectral Linewidth wavelength tunable laser diode with si wire waveguide ring resonators
Applied Physics Express, 2012Co-Authors: Keita Nemoto, Tomohiro Kita, Hirohito YamadaAbstract:We fabricated wavelength-tunable laser diodes with Si wire waveguide ring resonators as an external optical cavity. The footprint of the optical cavity including the semiconductor optical amplifier is as small as 2.73×0.89 mm2, which is about 1/5 of those made of silicon oxinitride material. About 44-nm-wavelength tuning operation, which covers the entire L-band of the optical communication wavelength range, was obtained. Furthermore, Spectral Linewidth narrower than 100 kHz was obtained by optimizing the design of the external optical cavity. The tunable laser diodes with narrow Spectral Linewidth are suitable as light sources for digital coherent optical transmission systems.
H Ishii - One of the best experts on this subject based on the ideXlab platform.
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narrow Spectral Linewidth operation 160 khz in widely tunable distributed feedback laser array
Electronics Letters, 2010Co-Authors: H Ishii, K Kasaya, H OohashiAbstract:The Spectral Linewidth has been reduced in a widely tunable distributed feedback laser array with a long cavity structure. A narrow Linewidth of less than 160 kHz is achieved over a 40 nm tuning range with a fibre output power of 20 mW.
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Spectral Linewidth reduction in widely wavelength tunable dfb laser array
IEEE Journal of Selected Topics in Quantum Electronics, 2009Co-Authors: H Ishii, K Kasaya, H OohashiAbstract:We have developed an L-band tunable distributed feedback laser array (TLA) with a new design to reduce the Spectral Linewidth. A wide wavelength tuning range of ~ 40 nm is obtained with a high fiber output power of 20 mW and a high side-mode suppression ratio of >50 dB in the TLA module. A narrow Linewidth of less than 580 kHz is achieved over the entire tuning range. Furthermore, we investigated the causes of Linewidth variation. We found that a TLA with a longer cavity is more tolerant to external feedback, which reduces the variation in Linewidth.
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reduced Spectral Linewidth 0 6 mhz in l band wavelength tunable dfb laser array
International Semiconductor Laser Conference, 2008Co-Authors: H Ishii, K Kasaya, H OohashiAbstract:A wavelength tunable DFB laser array is fabricated with a new design for Spectral Linewidth reduction. A narrow Linewidth of <0.6 MHz is obtained over the entire tuning range (~40 nm) with a high fiber output power of 20 mW.
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narrow Spectral Linewidth under wavelength tuning in thermally tunable super structure grating ssg dbr lasers
IEEE Journal of Selected Topics in Quantum Electronics, 1995Co-Authors: H Ishii, F Kano, Y Tohmori, Y Kondo, T Tamamura, Y YoshikuniAbstract:Narrow Spectral Linewidth characteristics are demonstrated in thermally wavelength tunable super-structure-grating distributed Bragg reflector (SSG-DBR) InGaAsP-InP lasers. SSG reflectors were fabricated with a multiple-phase-shift insertion method using electron-beam lithography. The phase distributions of the SSG's were optimized to obtain uniform reflection peaks. Incorporating thin-film Pt heaters into the lasers enables us to tune the lasing wavelength by the thermal effect. The device has a wide quasi-continuous tuning range of 40 nm with CW operation at room temperature. The Spectral Linewidths, frequency fluctuations, and tuning speed in thermal wavelength tuning were studied compared with those in electrical tuning. Experimental results showed that thermal tuning does not influence frequency fluctuations and Spectral Linewidths, but the tuning speed was slow. Narrow Spectral Linewidths below 400 kHz were achieved in a wide quasi-continuous tuning range of 40 mm. >
Tomohiro Kita - One of the best experts on this subject based on the ideXlab platform.
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narrow Spectral Linewidth silicon photonic wavelength tunable laser diode for digital coherent communication system
IEEE Journal of Selected Topics in Quantum Electronics, 2016Co-Authors: Tomohiro Kita, Rui Tang, Hirohito YamadaAbstract:We demonstrated wavelength tunable laser diodes with Si-wire waveguide ring resonators as an external optical cavity. The footprint of the optical cavity including the semiconductor optical amplifier is as small as 0.8 mm × 0.6 mm which is less 1/10 of those made of silicon oxinitride material. Wavelength tuning range of approximately 55 nm was demonstrated, which covers entire L-band of the optical communication wavelength system. Furthermore, a Spectral Linewidth narrower than 100 kHz was obtained by optimizing the design of the external optical cavity. The optical nonlinearity of silicon is described and the influence on laser oscillation is also discussed.
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narrow Spectral Linewidth silicon photonic wavelength tunable laser with highly asymmetric mach zehnder interferometer
Optics Letters, 2015Co-Authors: Rui Tang, Tomohiro Kita, Hirohito YamadaAbstract:We propose a narrow-Spectral-Linewidth silicon photonic wavelength-tunable laser with a novel external wavelength-tunable filter, which consists of two silicon ring resonators with different circumferences and a highly asymmetric Mach–Zehnder interferometer (MZI), the two optical paths of which have significantly different lengths. Calculations and experimental results indicated that the gain difference between longitudinal modes was increased by the highly asymmetric MZI. Consequently, a narrow Spectral Linewidth of 12 kHz and a stable single-mode oscillation were obtained.
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narrow Spectral Linewidth and high output power si photonic wavelength tunable laser diode
International Conference on Group IV Photonics, 2013Co-Authors: Tomohiro Kita, Keita Nemoto, Hirohito YamadaAbstract:We fabricated wavelength tunable laser diodes with Si photonic wire waveguide ring resonators as an external optical cavity. Less than 100 kHz narrow Spectral Linewidth was obtained with small footprint. Our wavelength tunable laser diode shows sufficient good performance for practical use in digital coherent optical transmission systems.
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narrow Spectral Linewidth wavelength tunable laser with si photonic wire waveguide ring resonators
International Conference on Group IV Photonics, 2012Co-Authors: Keita Nemoto, Tomohiro Kita, Hirohito YamadaAbstract:We fabricated wavelength tunable laser diodes with Si-wire waveguide ring resonators as an external optical cavity. Less than 100 kHz narrow Spectral Linewidth was obtained by optimizing design of the ring resonators. The wavelength tunable laser diodes with narrow Spectral Linewidth are suitable as light sources for digital coherent optical transmission systems.
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narrow Spectral Linewidth wavelength tunable laser diode with si wire waveguide ring resonators
Applied Physics Express, 2012Co-Authors: Keita Nemoto, Tomohiro Kita, Hirohito YamadaAbstract:We fabricated wavelength-tunable laser diodes with Si wire waveguide ring resonators as an external optical cavity. The footprint of the optical cavity including the semiconductor optical amplifier is as small as 2.73×0.89 mm2, which is about 1/5 of those made of silicon oxinitride material. About 44-nm-wavelength tuning operation, which covers the entire L-band of the optical communication wavelength range, was obtained. Furthermore, Spectral Linewidth narrower than 100 kHz was obtained by optimizing the design of the external optical cavity. The tunable laser diodes with narrow Spectral Linewidth are suitable as light sources for digital coherent optical transmission systems.
H Oohashi - One of the best experts on this subject based on the ideXlab platform.
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narrow Spectral Linewidth operation 160 khz in widely tunable distributed feedback laser array
Electronics Letters, 2010Co-Authors: H Ishii, K Kasaya, H OohashiAbstract:The Spectral Linewidth has been reduced in a widely tunable distributed feedback laser array with a long cavity structure. A narrow Linewidth of less than 160 kHz is achieved over a 40 nm tuning range with a fibre output power of 20 mW.
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Spectral Linewidth reduction in widely wavelength tunable dfb laser array
IEEE Journal of Selected Topics in Quantum Electronics, 2009Co-Authors: H Ishii, K Kasaya, H OohashiAbstract:We have developed an L-band tunable distributed feedback laser array (TLA) with a new design to reduce the Spectral Linewidth. A wide wavelength tuning range of ~ 40 nm is obtained with a high fiber output power of 20 mW and a high side-mode suppression ratio of >50 dB in the TLA module. A narrow Linewidth of less than 580 kHz is achieved over the entire tuning range. Furthermore, we investigated the causes of Linewidth variation. We found that a TLA with a longer cavity is more tolerant to external feedback, which reduces the variation in Linewidth.
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reduced Spectral Linewidth 0 6 mhz in l band wavelength tunable dfb laser array
International Semiconductor Laser Conference, 2008Co-Authors: H Ishii, K Kasaya, H OohashiAbstract:A wavelength tunable DFB laser array is fabricated with a new design for Spectral Linewidth reduction. A narrow Linewidth of <0.6 MHz is obtained over the entire tuning range (~40 nm) with a high fiber output power of 20 mW.
Makoto Okai - One of the best experts on this subject based on the ideXlab platform.
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strained multiquantum well corrugation pitch modulated distributed feedback laser with ultranarrow 3 6 khz Spectral Linewidth
Electronics Letters, 1993Co-Authors: Makoto Okai, Makoto Suzuki, T TaniwatariAbstract:Introducing a 1% compressive strained multiquantum-well (MQW) active layer into a corrugation-pitch-modulated distributed feedback (CPM-DFB) laser reduces the Linewidth floor (residual Linewidth for extrapolated infinite output power) to 2 kHz and results in a Linewidth-power product of 140 kHz mW. Strained MQW CPM-DFB lasers produced a 55 mW output with a Spectral Linewidth of only 3.6 kHz.
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tunable dfb lasers with ultra narrow Spectral Linewidth
Electronics Letters, 1993Co-Authors: Makoto Okai, T TsuchiyaAbstract:A Spectral Linewidth of less than 98kHz was achieved in three-section corrugation-pitch-modulated multiquantumwell distributed feedback (CPM-MQW-DFB) lasers over a tuning range of 1.3nm, while maintaining a constant output power of 10mW.
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factors limiting the Spectral Linewidth of cpm mqw dfb lasers
IEEE Photonics Technology Letters, 1992Co-Authors: Makoto Okai, T Tsuchiya, A Takai, Naoki ChinoneAbstract:A Spectral Linewidth of 56 kHz is achieved by a CPM-MQW-DFB (corrugation-pitch-modulated multiquantum-well distributed feedback) laser at an output power of 25 mW. To separate effects of the white noise and 1/f noise in limiting the Linewidth, the authors measured the delayed-heterodyne lineshape by using a short delay-fiber. The minimum Spectral Linewidth is shown to be limited by white noise. >
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corrugation pitch modulated mqw dfb lasers with narrow Spectral Linewidth
IEEE Journal of Quantum Electronics, 1991Co-Authors: Makoto Okai, T Tsuchiya, K Uomi, Naoki Chinone, Tatsuo HaradaAbstract:Narrow Spectral Linewidth lasers are developed for optical coherent transmission systems. To obtain a narrow Spectral Linewidth, a CPM (corrugation-pitch modulated) structure is introduced into 1200- mu m-long MQW-DFB (multi-quantum well distributed feedback) lasers. The CPM structure effectively suppresses the axial spatial hole burning effect and stabilized single-mode spectrum at high output powers. A Spectral Linewidth of 170 kHz was achieved at an output power of 25 mW. Details of corrugation fabrication method that makes the CPM structure possible are described. >
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effect of 1 f noise on the Spectral Linewidth of corrugation pitch modulated multiquantum well distributed feedback lasers at high output power
IEEE Photonics Technology Letters, 1991Co-Authors: Makoto Okai, T Tsuchiya, K Uomi, Naoki Chinone, Tatsuo HaradaAbstract:The mechanism by which Spectral Linewidth reduction saturates in CPM-MQW-DFB (corrugated-pitch-modulated multiquantum-well distributed feedback) lasers at high output powers is investigated by measuring the Spectral power density of their FM noise. Linewidth saturation is caused by the 1/f component of this noise. >
