三明治式双折射低通滤波器的研制

Design of sandwich based birefringence optical low pass filter

为了有效抑制高于CCD或者CMOS传感器的图像采样频率而出现的莫尔条纹,研制了一种二维三明治式双折射低通滤波器(OLPF)。其主要由三片双折射晶体平板构成三明治结构,并在前、后表面分别镀上红外截止膜和增透膜。对所研制的二维水晶光学低通滤波器进行了实验测试,空间频率测试表明对莫尔条纹有良好的抑制效果。结果表明,所研制的低通滤波器具有很高的自洁净性,与后端的CCD或者CMOS传感器匹配良好,对空间高频有较强的抑制作用。

In order to effectively suppresses is higher than the Moire fringe which the CCD or the CMOS sensor picture sampling frequency appears, two-dimensional sandwich based birefringence optical low pass filter （OLPF） is design, fabrication and tested in our laboratory. Our deviceis consists of two birefringence plates and a half wave plate. On the front and back surfaces of the OLPF, antireflection film and infrared cutting film were plated. The test results show that high spatial frequency and Moire fringe are restrained very well. These reveal that our crystal OLPF can match with the CCD or the CMOS sensor and have good restraining high spatial performance.