新型等效斜楔设计

针对现有的静态斜楔干涉具无法实现零光程差,并且对被测光的空间相干性要求较高,进而影响光谱反演的准确性和复杂性问题,提出了一种新型等效斜楔干涉具,该等效斜楔由两种折射率不同的材料构成,两个反射面完全垂直,干涉的两束光是由同一束光分开而得,因此对光的空间相干性无太高要求,并且可以实现零光程差。理论推导了该斜楔不同位置的光程差公式和光谱反演公式,并且设计了该等效斜楔,其最大光程差可达168.3 m,对光谱测量过程进行了仿真分析,结合最大光程差和所测光谱波段分析了线阵CCD的像元数要求。采用532 nm单纵模激光器和632.8 nm氦氖激光器进行了实验分析,实验结果得到中心波长误差小于0.2%。

Design of novel equivalent static wedge

Existing static wedge interferometer can not achieve zero optical path difference, and it requires a strict spatial coherence of light, thereby affecting the accuracy and complexity of spectral inversion. Therefore, a novel equivalent static wedge was proposed. It consists of two different refractive index material, and two reflective surfaces perfectly vertical. Because interference of two beams of light is derived from a beam of light, it is not strictly required about spatial coherence. Moreover, it contains zero optical path difference. By deducing and analyzing the optical path difference of the arbitrary wedge position, the formula of spectral inversion was deduced. Then the wedge was designed and processed by using two materials which were different refractive index, and its maximum optical path difference could reach 168.3 m. And the process of spectral inversion was simulated. Combining maximum optical path difference with the measured spectral band, the requirement of the linear CCD pixel count was analyzed. The wedge was analyzed by experiments which use 532 nm and 632.8 nm lasers. The results show that the spectral inversion center wavelength error is less than 0.2%.