一种引力波探测用高灵敏度四象限光电探测器

Research on High-sensitive Quad Photodetector for Gravity Waves Detection

摘要:

针对引力波探测空间天线激光干涉仪对四象限光电探测器提出的低噪声、高灵敏度、高带宽的要求,设计了一种四象限光电探测器芯片与读出电路混合集成的低噪声光电探测器。四象限光电探测器芯片采用四个性能一致的双耗尽区InGaAs PIN光电二极管单片集成结构,以降低二极管电容,减小象限间隔,提高灵敏度。通过PSPICE软件对由探测器芯片、低噪声跨阻放大读出电路构成的探测器模块进行了仿真,优化了电路参数,计算出相应的增益、带宽、噪声功率密度。性能测试表明,研制的集成式探测器模的-3dB带宽为28.3MHz,等效噪声功率密度为1.7pW/Hz1/2,象限增益一致性为0.76%,基本满足空间激光干涉仪的需求。

Abstract:

In responses to the requirements of low noise, high sensitivity and high bandwidth, a quad photodetector in space laser interferometry for detecting gravity waves is developed. The quad photodetector is a hybrid of quad photodetector chip and readout circuits, while the chip is made by four same InGaAs PIN photodiodes with double depletion regions, so as to lower the photodiode capacitance, narrow the gap between quadrants, and improve the detection sensitivity. The detection module integrated with photodetector chip and low-noise transimpedance amplification readout circuits was simulated by PSPICE. By optimizing the circuit parameters, the gain, bandwidth and noise power density were calculated. Test results show that the integrated detection module has a -3dB-bandwidth of 28.3MHz, and a noise power density of 1.7pW/Hz1/2, and the inconsistency between quadrants is 0.76%. Therefore, the quad photodetector can satisfy the basic requirements of space laser interferometry.