会聚光中的傅立叶变换透镜用于彩虹全息

Fourier transform lens used in rainbow holography with convergent light illumination

在提高激光能量利用率和增大成像面积前提下 ,为了尽量减小透镜口径 ,采用会聚光照明前傅立叶变换透镜。由于它在全息制版镜头对称面上形成实的频谱面 ,从而可进行空间滤波处理。结果 ,透镜口径由平行光照明时的 13 5mm减小到 98mm ,成像面直径达到 10 0mm ,曝光时间可缩短为原来的 1/5。由此可得出 ,会聚光照明的傅立叶变换光路 ,在减小透镜口径方面优于 4f系统。

In order to reduce the aperture of lens possibly in case of enhancing the utilization ratio of laser energy and enlarging imagery area,we illuminate the front Fourier transform lens with convergent light.For it can form a real frequency plane just on the symmetrical plane of holographic lens,we can carry on optical information processing.As a result,the aperture of lens has been lessened to 98mm from 135mm when being illuminated by parallel light,the diameter of imaging area is up to 100mm and the time of producing master plate is cut down to 1/5 of the previous one.In conclusion,Fourier transform lens with convergent light illumination is more advanced than 4f system in reducing the aperture.