星载高灵敏度平衡光电探测器研究

Research on High Sensitivity Balanced Photodetector for Space Application

设计了一种由平衡光电二极管芯片和跨阻放大器混合集成的星载高灵敏度平衡光电探测器。平衡光电二极管芯片采用双InP-InGaAs光电二极管单元单片集成的内平衡结构,以降低芯片自身噪声,提高探测器灵敏度。通过Cadence仿真软件对集成了正负双向电流输入电路、自动增益控制电路和反相器型输入电路的闭环放大器结构进行了仿真,得到等效噪声功率、带宽和增益三者之间的关系,制作出适配平衡光电二极管芯片的跨阻放大器。搭建1.55μm激光测试系统对研制的探测器进行性能测试,结果显示,其3dB带宽为1.58GHz,等效噪声功率密度为5.96pW/Hz^1/2,共模抑制比为42.04dB(@DC^1.58GHz),在相干激光通信系统中的接收灵敏度达到-61dBm。

Designed is an onboard balanced photoelectric detector with high sensitivity,which is composed of a balanced photodiode chip and a trans-impedance amplifier.The balanced photodiode chip adopts the internal balance structure of dual InP-InGaAs photodiode unit to reduce the noise of the chip itself and improve the detection sensitivity.The closed-loop amplifier integrated with positive and negative bi-directional current input circuit,automatic gain control circuit and inverter input circuit was simulated by Cadence software,and the relationship of the equivalent noise power,bandwidth and gain was obtained.Then a tran-resistance amplifier being adaptive to balanced photodiode chip was produced.A 1.55μm laser test system was set up to test the performance of the developed detector,and the results show that its 3 dB bandwidth of1.58 GHz,equivalent noise power density of 5.96 pW/Hz^1/2,and the common-mode rejection ratio of 42.04 dB(@DC^1.58 GHz)are realized,and the receiving sensitivity in the coherent laser communication system reaches-61 dBm.