用于激光防护非逆向反射双层闪耀光栅的研究

Research on the non-backward reflective double-layer blazed grating for the laser protection

摘要:

提出一种用于激光(工作波长为1064nm)防护的非逆反射双层闪耀光栅。以光栅方程、闪耀波长 和闪耀 角关系公式为基础,研究了双层闪耀光栅光线分布特性,分析了上下微结构闪耀角度关系； 设计了双层闪 耀光栅各特性参数,其上、下层光栅闪耀角分别为50°和6°,周期均为5.2μm,光学元件厚为0.5mm, 在下表面镀Ag反射膜。采用反应离子刻蚀(RIE)技术制作双层闪耀光栅,通过轮廓仪进行测 试。研究结果表明,双层 闪耀光栅的光学特性受微结构形状误差影响较大,当光线垂直照射双层闪耀光栅时,出射光 与入射光形成20°夹角,实现了激光非逆反射的目的。

Abstract:

A novel non-backward reflective doubl e-layer blazed grating,which is used for laser (1064nm) protection,is proposed.Based on the universal equation of the grating and the re lationship between blazed wavelength and blazed angle,the light distribution characteristic s of the double-layer blazed grating are studied.This paper analyzes the blazed angle′s relationship between the upp er and lower micro-structures,and the characteristic parameters of the double-layer blazed grating are designed. The upper and lower grating blazed angels are 50°and 6°,respectively,its perio d is 5.2μm and the thickness of the optical element is 0.5mm.The lower surface was coated with a silver reflective film.A double-layer blazed gr ating was fabricated by reactive ion etching (RIE) technique and the test was carried out by using the profile.It is shown that the optical properties of the double- layer blazed grating are seriously by the form error of the micro-structur e.As the light is vertical to the double-layer blazed grating,the angle between the incident laser and the exit l aser is 20°.It can achieve the laser reverse reflection.