发明授权
- 专利标题: Optical correlator using ferroelectric liquid crystal spatial light modulators and Fourier transform lenses
- 专利标题(中): 使用铁电液晶空间光调制器和傅里叶变换透镜的光相关器
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申请号: US226461申请日: 1994-04-12
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公开(公告)号: US5418380A公开(公告)日: 1995-05-23
- 发明人: Darren M. Simon , Steven A. Serati
- 申请人: Darren M. Simon , Steven A. Serati
- 申请人地址: MD Bethesda
- 专利权人: Martin Marietta Corporation
- 当前专利权人: Martin Marietta Corporation
- 当前专利权人地址: MD Bethesda
- 主分类号: G02B27/28
- IPC分类号: G02B27/28 ; G06E3/00 ; G06K9/74 ; G02B27/42
摘要:
An optical correlator uses ferroelectric liquid crystal spatial light modulators (FLC-SLM's) in both the reference and filter planes. The SLM's include an electrically addressable memory to store images in the form a two-dimensional array of reflective pixels beneath the FLC layer. The SLM's selectively rotate the polarization of the light reflected by each pixel in accordance with the stored image. In particular, a laser produces a polarized beam that is directed through a first polarizing beamsplitter and onto the reference SLM. This beamsplitter blocks unmodulated light reflected by the reference SLM and transmits modulated light through a set of Fourier tranform lenses. The resulting beam is directed through a second polarizing beam splitter onto a filter SLM that has been programmed with the complex conjugate of the Fourier transform of a desired target image. Unmodulated light reflected from the filter SLM is blocked by the second polarizing beamsplitter and modulated light is reflected by the second polarizing beamsplitter through a set of inverse Fourier transform lenses. A CCD camera detects any correlation peak produced by the inverse Fourier transform lenses. A computer system downloads images to the SLM's and analyzes the correlation peaks detected by the camera. A half-wave plate can be included between both sets of SLM's and polarizing beamsplitters to allow manual adjustment of the polarization of the incident beam entering the SLM.
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