激光通信作为一种通信手段，以其抗干扰能力强、保密性好、功率集中等优点，在**和民用等领域得到广泛应用。为满足激光通信系统使用要求，提高信噪比，对系统中的滤光膜进行研制。选用Ti3O5和SiO2作为镀膜材料，依据倍频设计和双波长增透原理完成了三带通、宽反射带滤光膜的设计。通过膜厚缩放比例和逆向工程方法分析膜厚累积误差，重点解决了膜厚监控误差大的问题。制备的滤光膜在532 nm 和1064 nm 处透射率大于90%，808 nm处透射率大于85%，(1550±20) nm 处透射率小于0.4%，满足该系统环境测试要求。

As a means of communication, laser communication is widely used in the military and civilian fields for its strong anti-interference ability, excellent confidentiality, and centralized optical power. Filter film is made to satisfy the requirements for laser communication systems and to improve the signal to noise ratio. Using Ti3O5 and SiO2 as coating materials, a three-band-pass and wide reflection band filter is designed according to the double frequency design and dual-wavelength anti-reflection principle. By using scale thickness and reverse engineering methods, the accumulative error is analyzed, and the problem of thickness monitoring error is solved. Transmittance of the filter is greater than 90% at 532 nm and 1064 nm, is higher than 85% at 808 nm, and is less than 0.4% at (1550± 20) nm, which meets environmental testing requirements of the communication system.