The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
F. Koyama - One of the best experts on this subject based on the ideXlab platform.
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optical Preamplifier using optical modulation of amplified spontaneous emission in saturated semiconductor optical amplifier
Journal of Lightwave Technology, 2004Co-Authors: T. Yamatoya, F. KoyamaAbstract:This paper demonstrates a novel optical Preamplifier using optical modulation of amplified spontaneous emission (ASE) emitted from a saturated semiconductor optical amplifier (SOA). Requirements on optical alignments and antireflection coating for SOAs can be relaxed and the elimination of an optical filter gives us a large tolerance of an input light wavelength in the proposed optical Preamplifier. A small-signal gain of a fabricated Preamplifier was over 13.5 dB for an input power of below -20 dBm. An optical gain bandwidth was over 60 nm. We measured the small-signal response of the optically modulated ASE. The 3 dB bandwidths at SOA bias currents of 200, 300, and 400 mA were 5.8, 12.6, and 16.5 GHz, respectively. We also investigated improvements in receiver sensitivities with the proposed optical Preamplifier. Our calculation shows a possibility of 10 dB improvement in receiver sensitivities by using the optical Preamplifier at 10 Gb/s. The measured receiver sensitivity was -22.7 dBm at 10 Gb/s with the optical Preamplifier, which is corresponding to an improvement of 2.5 dB in the receiver sensitivity. Further improvements of the receiver sensitivity can be expected by optimizing the structure of SOAs for saturating ASE.
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10 Gb/s operation of optical Preamplifier using inverted ASE signal of saturated semiconductor optical amplifier
Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 2002Co-Authors: T. Yamatoya, F. KoyamaAbstract:Summary form only given. Semiconductor optical amplifiers (SOAs) are attractive for use in metro optical networks as well as in access networks. We proposed an optical Preamplifier using the optical modulation of ASE in a saturated SOA. The proposed Preamplifier only needs a single connection between a fiber and the SOA, which relaxes requirements on AR coating and assembling with a single mode fiber. In addition, this Preamplifier can potentially avoid using a narrow-band optical filter. In this paper, we investigate the high-speed response of the Preamplifier and demonstrate 10 Gb/s operation. In our proposed Preamplifier, an input signal is converted to the modulation of the ASE due to the saturation characteristic in an SOA, resulting in the amplification of the signal. We investigated the high-speed response of the optical Preamplifier. We used a polarization insensitive GaInAsP bulk SOA. We also investigated the improvement in receiver sensitivity of the optical Preamplifier. We measured bit error rate (BER) curves with and without the optical Preamplifier. The minimum receiver sensitivity was improved by about 10, 8 and 7 dB for 2.5, 5 and 10 Gb/s signal, respectively.
Tomonori Sekiguchi - One of the best experts on this subject based on the ideXlab platform.
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0.5-V Low-$V _{\rm T}$ CMOS Preamplifier for Low-Power and High-Speed Gigabit-DRAM Arrays
IEEE Journal of Solid-State Circuits, 2010Co-Authors: Akira Kotabe, Yoshimitsu Yanagawa, Satoru Akiyama, Tomonori SekiguchiAbstract:A novel low-VT CMOS Preamplifier was developed for low-power and high-speed gigabit DRAM arrays. The sensing time of a sense amplifier (SA) with the proposed Preamplifier and its activation schemes at a data-line voltage of 0.5 V was 6 ns, which is 62% shorter than that of an SA using a conventional Preamplifier. By activating the proposed Preamplifier temporarily during the write cycle, the writing time was 16.3 ns, which is 72% shorter than the case without activation of the proposed Preamplifier, and this time is short enough to apply a DRAM array using the proposed Preamplifier to 1.6-Gbit/s/pin DDR3 SDRAM. The operating current of the memory array and its peripheral circuit including the proposed Preamplifier was reduced by 12% by reducing the data-line voltage from 0.8 to 0.5 V.
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CMOS low-VT Preamplifier for 0.5-V gigabit-DRAM arrays
2009 IEEE Asian Solid-State Circuits Conference, 2009Co-Authors: Akira Kotabe, Yoshimitsu Yanagawa, Satoru Akiyama, Tomonori SekiguchiAbstract:A novel CMOS low-VT Preamplifier suitable for low-voltage and high-speed mid-point sensing was developed for gigabit DRAM. This Preamplifier consists of a low-VT NMOS cross couple, a low-VT PMOS cross couple and a high-VT CMOS latch. The sensing speed of the proposed Preamplifier at data-line voltage of 0.5 V is 62% higher than that of a conventional Preamplifier. By activating the low-VT NMOS and PMOS cross couples temporarily during write operation, writing time is 72% shorter compared to the case with the high-VT CMOS latch only. Data-line charging current of a memory cell array with the proposed Preamplifier is reduced by 26% by decreasing data-line voltage from 0.8 to 0.5 V.
T. Yamatoya - One of the best experts on this subject based on the ideXlab platform.
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optical Preamplifier using optical modulation of amplified spontaneous emission in saturated semiconductor optical amplifier
Journal of Lightwave Technology, 2004Co-Authors: T. Yamatoya, F. KoyamaAbstract:This paper demonstrates a novel optical Preamplifier using optical modulation of amplified spontaneous emission (ASE) emitted from a saturated semiconductor optical amplifier (SOA). Requirements on optical alignments and antireflection coating for SOAs can be relaxed and the elimination of an optical filter gives us a large tolerance of an input light wavelength in the proposed optical Preamplifier. A small-signal gain of a fabricated Preamplifier was over 13.5 dB for an input power of below -20 dBm. An optical gain bandwidth was over 60 nm. We measured the small-signal response of the optically modulated ASE. The 3 dB bandwidths at SOA bias currents of 200, 300, and 400 mA were 5.8, 12.6, and 16.5 GHz, respectively. We also investigated improvements in receiver sensitivities with the proposed optical Preamplifier. Our calculation shows a possibility of 10 dB improvement in receiver sensitivities by using the optical Preamplifier at 10 Gb/s. The measured receiver sensitivity was -22.7 dBm at 10 Gb/s with the optical Preamplifier, which is corresponding to an improvement of 2.5 dB in the receiver sensitivity. Further improvements of the receiver sensitivity can be expected by optimizing the structure of SOAs for saturating ASE.
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10 Gb/s operation of optical Preamplifier using inverted ASE signal of saturated semiconductor optical amplifier
Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 2002Co-Authors: T. Yamatoya, F. KoyamaAbstract:Summary form only given. Semiconductor optical amplifiers (SOAs) are attractive for use in metro optical networks as well as in access networks. We proposed an optical Preamplifier using the optical modulation of ASE in a saturated SOA. The proposed Preamplifier only needs a single connection between a fiber and the SOA, which relaxes requirements on AR coating and assembling with a single mode fiber. In addition, this Preamplifier can potentially avoid using a narrow-band optical filter. In this paper, we investigate the high-speed response of the Preamplifier and demonstrate 10 Gb/s operation. In our proposed Preamplifier, an input signal is converted to the modulation of the ASE due to the saturation characteristic in an SOA, resulting in the amplification of the signal. We investigated the high-speed response of the optical Preamplifier. We used a polarization insensitive GaInAsP bulk SOA. We also investigated the improvement in receiver sensitivity of the optical Preamplifier. We measured bit error rate (BER) curves with and without the optical Preamplifier. The minimum receiver sensitivity was improved by about 10, 8 and 7 dB for 2.5, 5 and 10 Gb/s signal, respectively.
Akira Kotabe - One of the best experts on this subject based on the ideXlab platform.
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0.5-V Low-$V _{\rm T}$ CMOS Preamplifier for Low-Power and High-Speed Gigabit-DRAM Arrays
IEEE Journal of Solid-State Circuits, 2010Co-Authors: Akira Kotabe, Yoshimitsu Yanagawa, Satoru Akiyama, Tomonori SekiguchiAbstract:A novel low-VT CMOS Preamplifier was developed for low-power and high-speed gigabit DRAM arrays. The sensing time of a sense amplifier (SA) with the proposed Preamplifier and its activation schemes at a data-line voltage of 0.5 V was 6 ns, which is 62% shorter than that of an SA using a conventional Preamplifier. By activating the proposed Preamplifier temporarily during the write cycle, the writing time was 16.3 ns, which is 72% shorter than the case without activation of the proposed Preamplifier, and this time is short enough to apply a DRAM array using the proposed Preamplifier to 1.6-Gbit/s/pin DDR3 SDRAM. The operating current of the memory array and its peripheral circuit including the proposed Preamplifier was reduced by 12% by reducing the data-line voltage from 0.8 to 0.5 V.
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CMOS low-VT Preamplifier for 0.5-V gigabit-DRAM arrays
2009 IEEE Asian Solid-State Circuits Conference, 2009Co-Authors: Akira Kotabe, Yoshimitsu Yanagawa, Satoru Akiyama, Tomonori SekiguchiAbstract:A novel CMOS low-VT Preamplifier suitable for low-voltage and high-speed mid-point sensing was developed for gigabit DRAM. This Preamplifier consists of a low-VT NMOS cross couple, a low-VT PMOS cross couple and a high-VT CMOS latch. The sensing speed of the proposed Preamplifier at data-line voltage of 0.5 V is 62% higher than that of a conventional Preamplifier. By activating the low-VT NMOS and PMOS cross couples temporarily during write operation, writing time is 72% shorter compared to the case with the high-VT CMOS latch only. Data-line charging current of a memory cell array with the proposed Preamplifier is reduced by 26% by decreasing data-line voltage from 0.8 to 0.5 V.
K. Washio - One of the best experts on this subject based on the ideXlab platform.
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A wide-dynamic-range, high-transimpedance Si bipolar Preamplifier IC for 10-Gb/s optical fiber links
IEEE Journal of Solid-State Circuits, 1999Co-Authors: K. Ohhata, T. Masuda, K. Imai, R. Takeyari, K. WashioAbstract:A wide-dynamic-range, high-transimpedance Preamplifier IC for 10-Gb/s optical fiber links was developed using a 0.3-/spl mu/m Si bipolar process. The Preamplifier with a limiting amplifier enables a wide dynamic range from 16 /spl mu/App to 2.5 mApp and a high transimpedance of 1 k/spl Omega/ (2 k/spl Omega/ in the differential output mode). Moreover, careful circuit design achieves a transimpedance fluctuation of 0.5 dBR and an average equivalent input noise current density of 12 pA//spl radic/Hz. This Preamplifier IC has the highest transimpedance of any Si bipolar Preamplifier for 10-Gb/s operation. Thus, the Preamplifier is suitable for 10-Gb/s short-haul optical fiber links and can be used to provide a low-cost system.
