应用天文研究组知识库

电光强度调制一般是基于线性理论,在某些高精密系统中,其非线性误差分析对于系统的指标评定和误差校正具有一定意义。首先,详细推导了电光强度调制器在一般情况下的光强调制函数,并阐述了工作点的重要性;接着,对标准工作点及其附近的情况进行了非线性误差的计算分析,且分别给出了表达式;然后,从频域的角度讨论高次谐波对调制的影响;最后,在时域上比较不同调制深度下的实际调制和理想调制效果。公式推演和实验分析表明,工作点的高度稳定性和小信号调制可以减小非线性误差,这些误差可以定性定量地表示出来,有望通过补偿的方法提高电光强度调制系统的精度。

Electro-optic intensity modulation is usually based on linearity theorem. In some highly precise system, the nonlinear error analysis is significant for the property evaluation and error correction. Firstly, the light intensity modulation function was derived in detail under general condition. Then, the nonlinear errors as the system was running at the standard working point and around were analyzed. The expressions of the nonlinear errors above were given. The effect of ultra-harmonics on modulation was discussed. At last, the difference between actual modulation and ideal modulation were separately manifested in time domain to diverse modulation depths. Formula deduction and experimental analysis show that the high reliability of working point and small signal modulation can decease nonlinear error. These errors can be qualitatively and quantitively expressed, and the accuracy of electro-optic intensity modulation system can be improved through compensation.