基于多光束干涉原理，推导了高斯光束斜入射角度调谐窄带滤光片后的透射光强表达式.在此基础上研究了入射角对高斯光束的透射特性的影响.计算和实验结果表明：随着入射角的增大，透射光强的光斑会出现一定程度的展宽现象；当入射角度较小时，输出为单一光斑，但其光强峰值位置产生了一定的偏移，并不在呈现高斯分布；当入射角度较大时，输出则为一系列的离散光斑.

Based on the multibeam interference principle, a transmitting intensity expression of a Gaussian beam incidenting obliquely on an angletuned narrowband filter is derived. According to the result, the influence of the incidence angle on the transmission of a Gaussion beam is investigated theoretically. The calculation and experiment results show that the size of the transmitting beam spot is brodened obviously in oblique incidence. When the incident angle of the thinfilm filter is relatively small, the position of the peak of the transmitting beam is shifted and the beam is not in Gaussian distribution. When the incident angle of the filter is relatively large, the transmitting beam consists of a series of spaceseparated beams.