We demonstrate a low-noise,high-gain,and large-dynamic-range photodetector(PD)based on a junction field-effect transistor(JFET)and a charge amplifier for the measurement of quantum noise in Bell-state detection(BSD).P...We demonstrate a low-noise,high-gain,and large-dynamic-range photodetector(PD)based on a junction field-effect transistor(JFET)and a charge amplifier for the measurement of quantum noise in Bell-state detection(BSD).Particular photodiode junction capacitance allows the silicon N-channel JFET 2sk152 to be matched to the noise requirement for charge amplifier A250.The electronic noise of the PD is effectively suppressed and the signal-to-noise ratio(SNR)is up to 15 dB at the analysis frequency of 2.75 MHz for a coherent laser power of 50.08µW.By combining of the inductor and capacitance,the alternating current(AC)and direct current(DC)branches of the PD can operate linearly in a dynamic range from 25.06µW to 17.50 mW.The PD can completely meet the requirements of SNR and dynamic range for BSD in quantum optics experiments.展开更多
In order to suppress the noise of gyroscopes,the method based on lock-in amplifier and capacitor matching of the low-noise readout circuit is proposed. Firstly,the principle to suppress the noise by lock-in amplifier ...In order to suppress the noise of gyroscopes,the method based on lock-in amplifier and capacitor matching of the low-noise readout circuit is proposed. Firstly,the principle to suppress the noise by lock-in amplifier is analyzed,and the noise model of front end is proposed. Secondly,the noise optimization for the charge amplifier is presented according to the noise model of front end. Finally,a readout circuit is constructed by this approach. The measurement results show that the parasitic capacitance of front end is 18 p F,and the noise at resonant frequency( 4 k Hz) is 133 n V / Hz1 / 2,and the overall bias stability is 30° /h,and the noise level is 0. 003° /( s·Hz1 / 2). The noise of the gyroscope with the low-noise readout by this method is suppressed effectively.展开更多
Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper te...Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier （OTA） structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF/√H capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.展开更多
基金Project supported by the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(STIP)(Nos.2021L562 and 2022L573)the Key Research and Development Projects for Attarcting High-Level Scientific and Technological Talents to Lvliang City(No.2021RC-2-27)+3 种基金the Open Fund of the Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques(South China University of Technology)(No.2021-06)the Key Research and Development Projects in the Field of Social Development of Lvliang City(No.2022SHFZ43)Higher Education Reform and Innovation Project of Shanxi Province,China(Nos.J2021718,J2021744,and J2021717)the Innovation and Entrepreneurship Training Program for College Students,China(No.202310812012)。
文摘We demonstrate a low-noise,high-gain,and large-dynamic-range photodetector(PD)based on a junction field-effect transistor(JFET)and a charge amplifier for the measurement of quantum noise in Bell-state detection(BSD).Particular photodiode junction capacitance allows the silicon N-channel JFET 2sk152 to be matched to the noise requirement for charge amplifier A250.The electronic noise of the PD is effectively suppressed and the signal-to-noise ratio(SNR)is up to 15 dB at the analysis frequency of 2.75 MHz for a coherent laser power of 50.08µW.By combining of the inductor and capacitance,the alternating current(AC)and direct current(DC)branches of the PD can operate linearly in a dynamic range from 25.06µW to 17.50 mW.The PD can completely meet the requirements of SNR and dynamic range for BSD in quantum optics experiments.
文摘In order to suppress the noise of gyroscopes,the method based on lock-in amplifier and capacitor matching of the low-noise readout circuit is proposed. Firstly,the principle to suppress the noise by lock-in amplifier is analyzed,and the noise model of front end is proposed. Secondly,the noise optimization for the charge amplifier is presented according to the noise model of front end. Finally,a readout circuit is constructed by this approach. The measurement results show that the parasitic capacitance of front end is 18 p F,and the noise at resonant frequency( 4 k Hz) is 133 n V / Hz1 / 2,and the overall bias stability is 30° /h,and the noise level is 0. 003° /( s·Hz1 / 2). The noise of the gyroscope with the low-noise readout by this method is suppressed effectively.
基金supported by the National Natural Science Foundation of China(No.61106025)the CAS/SAFEA International Partnership Program for Creative Research Teams
文摘Abstract： This paper presents a charge-sensitive-amplifier （CSA） based readout circuit for capacitive microelectro-mechanical-system （MEMS） sensors. A continuous-time （CT） readout structure using the chopper technique is adopted to cancel the low frequency noise and improve the resolution of the readout circuits. An operational trans-conductance amplifier （OTA） structure with an auxiliary common-mode-feedback-OTA is proposed in the fully differential CSA to suppress the chopper modulation induced disturbance at the OTA input terminal. An analog temperature compensation method is proposed, which adjusts the chopper signal amplitude with temperature variation to compensate the temperature drift of the CSA readout sensitivity. The chip is designed and implemented in a 0.35μm CMOS process and is 2.1 × 2.1 mm2 in area. The measurement shows that the readout circuit achieves 0.9 aF/√H capacitive resolution, 97 dB dynamic range in 100 Hz signal bandwidth, and 0.8 mV/fF sensitivity with a temperature drift of 35 ppm/℃ after optimized compensation.
