光外差系统噪声等效功率的一种测量方法

Measurement of noise equivalent power of optical heterodyne system

本文介绍了利用工作于Bragg衍射的Ge晶体声光调制器作为外差系统中的频移器来测量外差系统的噪声等效功率(NEP)的方法。该方法具有测试系统简单、信号光功率、偏频可调的优点。实验测试与理论分析吻合。

In this paper, the noise equivalant power (NEP) of optical heterodyne system has been measured with a method based on acousto-optici germanium' crystal modulator working at Bragg diffraction mode as a frequency shifting device in heterodyne system. This method has the advantages of simple structure, easy change of signal power and shifted frequency. The experimental results are found in argreement with the theoretical analysis.