调制偏振光在光学相位延迟测量中的频谱分析

介绍了光调制器的调制原理,在时间域和频率域对其调制特性进行了理论分析,得到了相应的光强分布曲线.基于偏振光调制理论,提出了一种新型光学相位延迟测量方法,并对该方法从时域和频域两方面进行了分析.频谱分析的结果表明,当出射光信号的奇次谐频分量为零时,满足完全补偿条件,此时可由补偿器的补偿量直接得到待测器件的光学相位延迟量.这种方法能够对光学相位延迟量进行直接量的测量,和其他间接测量方法相比有其明显的优势.在理论分析的基础上,还进行了相应的实验,并得到了高精度的实验结果.

Spectrum Analysis of Modulated Polarized Light in Phase Retardation Measurement

The fundamental principle of light modulation is presented.The characteristic of light modulator is discussed both in time and frequency domains.Fourier transform spectrum of the intensity shows that the intensity distribution of outgoing light is the superposition of a series of Dirac functions in the frequency domain.The corresponding intensity distribution curves are also presented.A novel method for phase retardation measurement based on modulated polarized light is introduced.The spectrum analysis indicates that the perfect compensation condition can be satisfied only when the odd frequency components disappear.Under this condition,the phase retardation to be detected can be directly obtained from the compensation quantity of the compensator.This method is a direct measurement which is clearly superior to those indirect methods,especially in terms of high accuracy and low error.Based on the theoretical analysis,relevant experiments were conducted.And experimental results with high precision were obtained.