格兰-泰勒棱镜的改进设计及其特性

为了消除格兰-泰勒(Glan-Taylor)棱镜(GTP)空气隙造成的干涉并提高透射比,设计并制造了一种改进型格兰-泰勒棱镜。在设计中应用了菲涅耳理论、布儒斯特定律。新棱镜改变了第二劈的结构角使e光以布儒斯特角入射第二劈入射面。为了尽量减小新棱镜的偏离角,还设计了补偿角。理论和实验均证明相对于原格兰-泰勒棱镜,新棱镜在宽光谱范围内有更高的透射比。由于新棱镜中空气隙尖角较大,达12.65°,并且e光以布儒斯特角入射第二劈,所以无干涉现象。实验证明,新棱镜旋转时透射曲线无明显抖动,入射光波长在540~670 nm频谱范围内变化时,新棱镜透射光束的偏离角小于5′。

Modified Glan-Taylor Prisms and Its Characteristics

In order to improve transmittivity and eliminate interference induced by air-gap in a Glan-Taylor prism (GTP), a modified GTP was designed and fabricated. In the new design, Fresnel theory and Brewster′s law were used. In the new prism, the structure angles of the second half prism were modified so that extraordinary ray is incident with Brewster angle. In order to minimize the deviation angle of the new prism, an additional angle was designed. Theory and experiments have confirmed that the new prism has higher transmittance than a common one in a wide wavelength range. The interference effect will not occur in the new prism for its large wadge angle of air-gap (12.65°) and the incidence with Brewster angle of extraordinary ray on the second half prism . Experimentally, there is no clear “minute fluctuation” on the transmission curve of the new polarizing prism when it is rotated, and its deviation angle is smaller than 5′ in the wavelength range of 540～670 nm.