| With continuously enlarging of laser application in the fields of military, medicine and industry, the security of people and opto-electric detection systems are facing with enormous risk, so it is necessary to take some protection measures for the optical components. Aiming at the wavelengths of 532nm and 1064nm, which are the two common wavelengths of lasers, it has great research meaning and practical value for us to develop a dual-band notch filter that can efficiently defend the 532nm and 1064nm lasers by thin-film interference technology to protect human eyes and infrared opto-electric systems.The researches on film design method of dual-band notch filter were investigated in this paper, and dual-band notch filter was successfully prepared by PECVD technology. Firstly, film design methods of 532nm and 1064nm dual-band notch filter were studied based on different film design theories. Six kinds of film schemes were achieved by means of design and optimization, and the optimized film structure was confirmed by comparison. Secondly, the process technology and optimal process parameters of SiNx materials, SiOxNy materials and SiOxFy materials were researched by PECVD technology. Finally, the dual-band notch filter working at the wavelengths of 532nm and 1064nm was successfully manufactured by PECVD technology, and the errors of test results were analyzed. Some main conclusions are as follows:(1) A variety of film structures that meet the required design index can be achieved by choosing proper initial film structures from traditional HL film structure, Rugate film structure, hybrid and gradient film structure, and combining with some optimization methods. The film structure, Al2O3|(0.5L3M0.5L)2(0.5L3H0.5L)8 (0.5L3M0.5L)2|air, has good spectral properties. From the point of view of optimization, it is easy to achieve higher performance, and the optimal design result can be obtained by optimization with the gradient method. Besides, from the perspective of manufacture, it is easy to be prepared because it only needs three kinds of materials, and it has less layers, thin total thickness, the geometrical thickness of thinnest layer is also not too small.(2) The monolayer films of SiOxFy, SiOxNy and SiNx that are prepared with optimal process parameters have good process stability. The refractive index errors of monolayer films are all less than 1.5%, and thickness errors of monolayer films are all less than 5%.(3) The average transmittance of 532nm and 1064nm dual-band notch filter that is prepared by PECVD technology at the waveband ranging from 400nm to 480nm,600 nm to 700nm and 3000 to 5000nm is 86.18%, and the transmittance at the wavelengths of 532nm and 1064nm are 0.94% and 3.55%, respectively. |
