半导体激光器光输出噪声测量及与电噪声的相关性

Measurement of Light Output Noise of Semiconductor Lasers and Its Correlation with Electrical Noise

采用互谱估计方法测量了半导体激光器的微弱电噪声谱及光噪声谱。结果表明两者在超辐射区有较强的相关性。对光噪声的形成机理分析证明由载流子起伏形成的光噪声与电噪声完全相关，而由外量子效率起伏引起的光噪声与电噪声是不相关的。

In this paper, the experimental set-up used for measuring the light output noise of a laser diode has been established. A weak electrical noise and light output noise can be measured by using the cross-spectrum approach. Experimental results obtained for 30 Vgroove InP/InGaAsP lasers at frequency region from 1 Hz to 100 kHz demonstrated that the light output noise and electrical noise is correlative in the superradiation region, and its spectrum form is also similar. According to the mechanism of light excitation in LD, the light output noise has been discussed. The theoritical analysis shows that the light output noise is separated into two parts, one caused by carriers fluctuation is full correlative with electrical noise, another caused by light quantum fluctuation is uncorrelative with electrical noise.