The Experts below are selected from a list of 6966 Experts worldwide ranked by ideXlab platform
Chia Hua Chuang - One of the best experts on this subject based on the ideXlab platform.
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synthesizing genetic sequential logic circuit with Clock Pulse generator
BMC Systems Biology, 2014Co-Authors: Chia Hua Chuang, Chunliang LinAbstract:Rhythmic Clock widely occurs in biological systems which controls several aspects of cell physiology. For the different cell types, it is supplied with various rhythmic frequencies. How to synthesize a specific Clock signal is a preliminary but a necessary step to further development of a biological computer in the future. This paper presents a genetic sequential logic circuit with a Clock Pulse generator based on a synthesized genetic oscillator, which generates a consecutive Clock signal whose frequency is an inverse integer multiple to that of the genetic oscillator. An analogous electronic waveform-shaping circuit is constructed by a series of genetic buffers to shape logic high/low levels of an oscillation input in a basic sinusoidal cycle and generate a Pulse-width-modulated (PWM) output with various duty cycles. By controlling the threshold level of the genetic buffer, a genetic Clock Pulse signal with its frequency consistent to the genetic oscillator is synthesized. A synchronous genetic counter circuit based on the topology of the digital sequential logic circuit is triggered by the Clock Pulse to synthesize the Clock signal with an inverse multiple frequency to the genetic oscillator. The function acts like a frequency divider in electronic circuits which plays a key role in the sequential logic circuit with specific operational frequency. A cascaded genetic logic circuit generating Clock Pulse signals is proposed. Based on analogous implement of digital sequential logic circuits, genetic sequential logic circuits can be constructed by the proposed approach to generate various Clock signals from an oscillation signal.
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synthesizing genetic sequential logic circuit with Clock Pulse generator
BMC Systems Biology, 2014Co-Authors: Chia Hua ChuangAbstract:Background Rhythmic Clock widely occurs in biological systems which controls several aspects of cell physiology. For the different cell types, it is supplied with various rhythmic frequencies. How to synthesize a specific Clock signal is a preliminary but a necessary step to further development of a biological computer in the future.
Yoshihito Amemiya - One of the best experts on this subject based on the ideXlab platform.
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low power temperature to frequency converter consisting of subthreshold cmos circuits for integrated smart temperature sensors
Sensors and Actuators A-physical, 2011Co-Authors: Ken Ueno, Tetsuya Asai, Yoshihito AmemiyaAbstract:Abstract A low-power temperature-sensing oscillator was developed using a 0.35- μ m standard CMOS process. This oscillator generates a Clock Pulse whose frequency is proportional to absolute temperature (PTAT frequency). It consists of a PTAT current generator controlled with an external reference Clock and a frequency-locked loop biased with an external reference voltage. The PTAT current generator makes use of the exponential current characteristic of MOSFETs operated in the subthreshold region. Theoretical analyses and experimental results showed that the circuit can be used as a temperature sensor with a low-power consumption of 10 μ W or less. The temperature coefficient of the output frequency was insensitive to variation in device parameters, so the sensor circuit can be used only with one-point calibration. Its temperature-sensing error was from − 1.8 to + 1 ° C in a temperature range of 10–80 ° C. This temperature sensor would be suitable for use in subthreshold-operated, power-aware LSIs.
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low power temperature to frequency converter consisting of subthreshold cmos circuits for integrated smart temperature sensors
Sensors and Actuators A-physical, 2011Co-Authors: Ken Ueno, Tetsuya Asai, Yoshihito AmemiyaAbstract:Abstract A low-power temperature-sensing oscillator was developed using a 0.35- μ m standard CMOS process. This oscillator generates a Clock Pulse whose frequency is proportional to absolute temperature (PTAT frequency). It consists of a PTAT current generator controlled with an external reference Clock and a frequency-locked loop biased with an external reference voltage. The PTAT current generator makes use of the exponential current characteristic of MOSFETs operated in the subthreshold region. Theoretical analyses and experimental results showed that the circuit can be used as a temperature sensor with a low-power consumption of 10 μ W or less. The temperature coefficient of the output frequency was insensitive to variation in device parameters, so the sensor circuit can be used only with one-point calibration. Its temperature-sensing error was from − 1.8 to + 1 ° C in a temperature range of 10–80 ° C. This temperature sensor would be suitable for use in subthreshold-operated, power-aware LSIs.
David J Moss - One of the best experts on this subject based on the ideXlab platform.
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sub picosecond phase sensitive optical Pulse characterization on a chip
Nature Photonics, 2011Co-Authors: Alessia Pasquazi, Marco Peccianti, Yongwoo Park, Brent E Little, Roberto Morandotti, Jose Azana, David J MossAbstract:he recent introduction of coherent optical communications has created a compelling need for ultrafast phase-sensitive measurement techniques operating at milliwatt peak power levels and in timescales ranging from sub-picoseconds to nanoseconds. Previous reports of ultrafast optical signal measurements in integrated platforms include time-lens temporal imaging on a silicon chip and waveguide-based frequency-resolved optical gating (FROG). Time-lens imaging is phase-insensitive, and waveguide-based FROG methods require the integration of long tunable delay lines, which is still an unsolved challenge. Here, we report a device capable of characterizing both the amplitude and phase of ultrafast optical Pulses with the aid of a synchronized incoherently related Clock Pulse. It is based on a novel variation of spectral phase interferometry for direct electric-field reconstruction (SPIDER) that exploits degenerate four-wave mixing in a CMOS-compatible chip. We measure Pulses with a peak power of 1 THz, and up to 100 ps Pulsewidths, yielding a timeg-bandwidth product of >100.
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sub picosecond phase sensitive optical Pulse characterization on a chip
Nature Photonics, 2011Co-Authors: Alessia Pasquazi, Marco Peccianti, Yongwoo Park, Brent E Little, Roberto Morandotti, Jose Azana, Sai T Chu, David J MossAbstract:he recent introduction of coherent optical communications has created a compelling need for ultrafast phase-sensitive measurement techniques operating at milliwatt peak power levels and in timescales ranging from sub-picoseconds to nanoseconds. Previous reports of ultrafast optical signal measurements in integrated platforms include time-lens temporal imaging on a silicon chip and waveguide-based frequency-resolved optical gating (FROG). Time-lens imaging is phase-insensitive, and waveguide-based FROG methods require the integration of long tunable delay lines, which is still an unsolved challenge. Here, we report a device capable of characterizing both the amplitude and phase of ultrafast optical Pulses with the aid of a synchronized incoherently related Clock Pulse. It is based on a novel variation of spectral phase interferometry for direct electric-field reconstruction (SPIDER) that exploits degenerate four-wave mixing in a CMOS-compatible chip. We measure Pulses with a peak power of 1 THz, and up to 100 ps Pulsewidths, yielding a timeg-bandwidth product of >100.
R Takahashi - One of the best experts on this subject based on the ideXlab platform.
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self stabilizing optical Clock Pulse train generator using soa and saturable absorber for asynchronous optical packet processing
Optics Express, 2013Co-Authors: T Nakahara, R TakahashiAbstract:We propose a novel, self-stabilizing optical Clock Pulse-train generator for processing preamble-free, asynchronous optical packets with variable lengths. The generator is based on an optical loop that includes a semiconductor optical amplifier (SOA) and a high-extinction spin-polarized saturable absorber (SA), with the loop being self-stabilized by balancing out the gain and absorption provided by the SOA and SA, respectively. The optical Pulse train is generated by tapping out a small portion of a circulating seed Pulse. The convergence of the generated Pulse energy is enabled by the loop round-trip gain function that has a negative slope due to gain saturation in the SOA. The amplified spontaneous emission (ASE) of the SOA is effectively suppressed by the SA, and a backward optical Pulse launched into the SOA enables overcoming the carrier-recovery speed mismatch between the SOA and SA. Without external control for the loop gain, a stable optical Pulse train consisting of more than 50 Pulses with low jitter is generated from a single 10-ps seed optical Pulse even with a variation of 10 dB in the seed Pulse intensity.
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optical Clock Pulse train generator for processing preamble free asynchronous optical packets
IEEE Photonics Technology Letters, 2006Co-Authors: T Nakahara, R Takahashi, T Yasui, H SuzukiAbstract:An optical Clock-Pulse-train generator (OCPTG) for processing asynchronous arbitrary-length optical packets with no preamble is developed. The OCPTG consists of a fiber-loop-based optical Pulse-train generator (PTG) and an optical Clock-Pulse generator that, for every input asynchronous optical packet, generates a single, synchronized optical Pulse which is fed to the PTG. Generation of an optical Clock-Pulse-train with stable Pulse energy, precise repetition rate, and duration matching the input packet is achieved for variable-length optical packets. The OCPTG and an all-optical demultiplexer combined demonstrate error-free demultiplexing of a 10-Gb/s asynchronous optical packet stream
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optical Clock Pulse train generator for asynchronous arbitrary length optical packet processing
Optical Fiber Communication Conference, 2006Co-Authors: T Nakahara, R Takahashi, T Yasui, H SuzukiAbstract:An optical Clock Pulse-train generator (OCPTG) for processing asynchronous arbitrary-length optical packets with no preamble is developed for the first time. Error-free demultiplexing for 10-Gbit/s asynchronous optical packets is achieved using the OCPTG.
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ultrafast optoelectronic packet processing for asynchronous optical packet switched networks invited
Journal of Optical Networking, 2004Co-Authors: R Takahashi, Tatsushi Nakahara, Kiyoto Takahata, Hirokazu Takenouchi, T Yasui, Naoto Kondo, H SuzukiAbstract:Feature Issue on Optical Interconnection Networks (OIN). We describe hybrid optical-electrical systems that perform header processing and buffering of ultrafast, asynchronous optical packets. Our systems are enabled by three key, novel devices: an all-optical serial-to-parallel converter, an optical Clock-Pulse generator, and a photonic parallel-to-serial-converter. These devices allow utilization of complementary metal-oxide semiconductor technology for compact, highly functional optical packet processing. A simplified node architecture for asynchronous, optical- packet-switched networks is made possible by these systems with all the necessary node functions integrated compactly. We also demonstrate an optical label swapper and a photonic random access memory for 40-Gbit/s, 16-bit, asynchronous optical packets.
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packet level optical timing Pulse generator and its application to 40 gbit s optical packet self routing
2004Co-Authors: Tatsushi Nakahara, R Takahashi, Hirokazu TakenouchiAbstract:We describe a novel packet-level optical timing-Pulse (Clock-Pulse) generator that generates one optical Pulse per incoming asynchronous burst optical packet: the generated optical Pulse is accurately synchronized with the input optical packet. We also describe 40-Gbit/s optical packet self-routing based on 40-Gbit/s 16-bit serial optical-label recognition by a CMOS (complementary metal-oxide-semiconductor) circuit operated together with an all-optical serial-to-parallel converter and the optical timing-Pulse generator.
Marco Peccianti - One of the best experts on this subject based on the ideXlab platform.
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sub picosecond phase sensitive optical Pulse characterization on a chip
Nature Photonics, 2011Co-Authors: Alessia Pasquazi, Marco Peccianti, Yongwoo Park, Brent E Little, Roberto Morandotti, Jose Azana, David J MossAbstract:he recent introduction of coherent optical communications has created a compelling need for ultrafast phase-sensitive measurement techniques operating at milliwatt peak power levels and in timescales ranging from sub-picoseconds to nanoseconds. Previous reports of ultrafast optical signal measurements in integrated platforms include time-lens temporal imaging on a silicon chip and waveguide-based frequency-resolved optical gating (FROG). Time-lens imaging is phase-insensitive, and waveguide-based FROG methods require the integration of long tunable delay lines, which is still an unsolved challenge. Here, we report a device capable of characterizing both the amplitude and phase of ultrafast optical Pulses with the aid of a synchronized incoherently related Clock Pulse. It is based on a novel variation of spectral phase interferometry for direct electric-field reconstruction (SPIDER) that exploits degenerate four-wave mixing in a CMOS-compatible chip. We measure Pulses with a peak power of 1 THz, and up to 100 ps Pulsewidths, yielding a timeg-bandwidth product of >100.
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sub picosecond phase sensitive optical Pulse characterization on a chip
Nature Photonics, 2011Co-Authors: Alessia Pasquazi, Marco Peccianti, Yongwoo Park, Brent E Little, Roberto Morandotti, Jose Azana, Sai T Chu, David J MossAbstract:he recent introduction of coherent optical communications has created a compelling need for ultrafast phase-sensitive measurement techniques operating at milliwatt peak power levels and in timescales ranging from sub-picoseconds to nanoseconds. Previous reports of ultrafast optical signal measurements in integrated platforms include time-lens temporal imaging on a silicon chip and waveguide-based frequency-resolved optical gating (FROG). Time-lens imaging is phase-insensitive, and waveguide-based FROG methods require the integration of long tunable delay lines, which is still an unsolved challenge. Here, we report a device capable of characterizing both the amplitude and phase of ultrafast optical Pulses with the aid of a synchronized incoherently related Clock Pulse. It is based on a novel variation of spectral phase interferometry for direct electric-field reconstruction (SPIDER) that exploits degenerate four-wave mixing in a CMOS-compatible chip. We measure Pulses with a peak power of 1 THz, and up to 100 ps Pulsewidths, yielding a timeg-bandwidth product of >100.