为了在不影响干涉条纹成像质量的基础上通过增大双折射棱镜结构角的方法获得更细致的光谱成分,优化设计了双折射棱镜的结构。通过计算分束角与结构角之间的函数关系,分析得知在传统双折射棱镜后附加一个与第二个楔形同性质的等腰三角形棱镜,使出射棱镜的o光和e光平行于光轴,即分束角α为0°,从而干涉条纹的成像不再受分束角的变化所影响。并将优化的双折射棱镜制成棱镜组以进一步提高光谱分辨率。实验分别采用传统双折射棱镜组和优化的双折射棱镜组对980nm的激光光源进行测量。实验数据可知,采用优化的双折射棱镜组得到的干涉条纹对比度更清晰,对应由DSP傅里叶变换得到的光谱数据也更精确。
In order to not affect the image quality of interference fringes on the basis of the structure by increasing the structure angle of Wollaston prism to improve spectrum resolution,the authors optimized the structure of Wollaston prism.Calculating the function of the splitting angle and the structure angle,analysis indicated that taking the isosceles triangle prism with the same nature of the second wedge-shaped prism after the Wollaston prism,which makes the o and e light parallel to the optical axis,and α=0°,the imaging interference fringes are no longer affected by changes in the splitting angle.Several optimized Wollaston prisms were made as an array to improve the spectral resolution.Experiments used traditional and optimized Wollaston prism array to detect the spectrum of the 980 nm laser.Experimental data showed that using optimized Wollaston prism array gets a clearer contrast of interference fringes,and the spectral data with Fourier transform are more accurate with DSP.