面向多频段激光强度噪声抑制的低噪声光电探测技术研究  

Low-noise Photodetection Technology for Multiband Laser-intensity-noise Suppression

作　　者：张震[1] 郭长磊 ZHANG Zhen;GUO Changlei(MOE Key Laboratory of TianQin Mission,TianQin Research Center for Gravitational Physics&School of Physics and Astronomy,Frontiers Science Center for TianQin,CNSA Research Center for Gravitational Waves,Sun Yat-sen University(Zhuhai Campus),Zhuhai 519082,China)

机构地区：[1]“天琴计划”教育部重点实验室,中山大学天琴中心&物理与天文学院,天琴前沿科学中心,国家航天局引力波研究中心,珠海519082

出　　处：《光子学报》2025年第2期98-111,共14页Acta Photonica Sinica

基　　金：国家自然科学基金(No.12404489);中山大学中央高校基本科研业务费专项资金(No.24QNPY162);国家重点研发计划(No.2020YFC2200200);广东省基础与应用基础研究重大项目(No.2019B030302001)。

摘　　要：立足于空间引力波探测对NPRO激光器多频段强度噪声的抑制需求,设计完成一款可用于实现NPRO激光器毫赫兹频段强度噪声和中频段弛豫振荡峰同时探测的低噪声光电探测器。该光电探测器采用零漂移运算放大器与高速运算放大器相结合的电路拓扑结构实现毫赫兹频段内低探测噪声的同时具备15 MHz的探测带宽。该光电探测器的噪声在0.1 m Hz~1Hz频段内的绝对噪声水平低于1×10^(-7)V/Hz^(1/2),在100 k Hz~1 MHz内绝对噪声水平低于2×10^(-8)V/Hz^(1/2)。实测结果显示在0.1 m Hz~1 Hz频段内的绝对噪声水平低于1×10^(-6)V/Hz^(1/2),在100 k Hz~1 MHz内绝对噪声水平低于5×10^(-8)V/Hz^(1/2)。实际噪声水平可满足空间引力波项目对NPRO激光器毫赫兹频段内强度噪声和中频段弛豫振荡峰的探测需求,可用于相关噪声抑制实验研究。The high-intensity noises of free-running lasers cannot meet the stringent requirements in the field of precision measurements such as gravitational wave detection.Taking ground-based gravitational wave detection project The Laser Interferometer Gravitational Wave Observatory(LIGO)as an example,its detection sensitivity was significantly improved after suppressing the laser intensity noises in the frequency range of 10 Hz to 10 kHz,which helps to directly observe the first gravitational wave signal in 2015.In order to obtain more information about the universe,researchers have attempted to expand the detection range of gravitational wave to the millihertz frequency range.So far,a few projects on space gravitational wave detection have been initiated around the world.Taking The Laser Interferometer Space Antenna(LISA)and Tianqin as examples,the space gravitational wave projects require laser sources to have their relative intensity noises below 2×10^(-4) Hz-^(1/2)in the millihertz frequency range,2×10^(-6)Hz-^(1/2)in the 100 s kilohertz frequency range and 1×10^(-8)Hz-^(1/2)in the megahertz frequency range.The seed lasers used in such projects are Non-Planar-Ring-Oscillators(NPRO)solid-state lasers,which have high intensity noises in the millihertz frequency range and high relaxation-oscillation noises in the 100 s kilohertz frequency range.Active noise suppression using feedback control loop must be applied on such lasers to meet the low-intensity noise requirements.The photodetector is one of the key components in active feedback control loop to convert optical signal to electrical signal with high efficiency and low noise.Motivated by the simultaneous suppression of millihertz intensity noise and 100 s kilohertz relaxation-oscillation noises in NPRO lasers,a wide-bandwidth and low-noise photodetector has been designed and tested in this work.The design strategies of this photodetector mainly include the following four points:firstly,select low-noise and high-response PIN-type InGaAs photodiodes to operate in

关 键 词：空间引力波探测 激光强度噪声 光电探测技术 主动噪声抑制 噪声分析 

分 类 号：TH744[机械工程—光学工程]