高斯光束斜入射非平行薄膜滤光片的反射光强分布

基于多光束干涉原理,推导了非平行角度调谐薄膜滤光片在斜入射时的高斯光束反射光强表达式。在此基础上研究了高斯光束的入射角以及非平行滤光片两端面间所存在楔角对反射光强分布的影响。计算和实验结果都表明,滤光片的反射光强分布不仅与入射角有关,而且非平行滤光片两端面间楔角的大小和正负特性还会在一定程度上影响斜入射时滤光片的光场分布、反射率和隔离度。要保证滤光片在斜入射时反射率和隔离度的稳定,既可以在切片时提高滤光片的平行度,也可以通过在斜入射时保证楔角为负来实现。

Reflected-Intensity Distribution of a Thin-Film Filter with Oblique Incidence of a Gaussian Beam Under-Parallel Case

Based on the multi-beam interference principle, a Gaussian beam reflected-intensity expression on a non-parallel angle-tuned thin-film filter in oblique incidence is derived. The influence of the reflected-intensity distribution with different incident angles, especially with different wedge angles of the non-paralleled thin-film filter is analyzed theoretically. Calculation and experimental results show that the reflected-intensity distribution, reflected-peak and the isolation degree are influenced by the wedge angle, incident angle and polarity of the wedge angle. In order to get stable reflected-characteristics and high isolation degree, the parallelism of the angle-tuned thin-film filter should be improved in fabrication or the polarity of the wedge angle in oblique incidence should be negative.