用计算全息标校补偿器的技术

Certification of Compensator by Computer-Generated Hologram

用计算全息(CGH)模拟理想非球面主镜的反射波面,用补偿器对该计算全息进行检验,只要计算全息的制作误差能够满足要求,就能实现直接对补偿器的标校。介绍了计算全息标校补偿器的原理、方法,并进行了误差分析。实验采用电子束制作的计算全息实现了对850 mm F/2抛物面主镜补偿器的标校,补偿器产生的标准非球面精度不低于计算全息模拟的主镜面形精度,均方根(RMS)误差为0.012λ。研究表明,用计算全息模拟主镜反射波面对补偿器进行标校是一种行之有效的方法,结合先进的微电子制造技术,可实现对补偿器的高精度标校。

The certification is performed through directly testing the computer-generated hologram（CGH） which is used to synthesize the wavefront reflected by a perfect primary mirror. If the errors of computer-generated hologram are within the requirement, the certification can be realized. The principle and methods of certification by computergenerated hologram are introduced ,and its errors are analyzed. Using the computer-generated hologram written by electronic beam lithography, the compensator for Φ850 mm F/2 parabolic mirror is certified, and the standard aspherical precision created by the compensator is not less than the primary mirror precision synthesized by computer-generated hologram, the root mean square（RMS） error is 0. 012λ. The results show that it＇s an effective way to certify the compensator by simulating the wavefront reflected by perfect primary with computer-generated hologram. Combining the sophisticated lithographical manufacturing technology, high-precision certification can be achieved.