Heifetz A, Pati G S, Shen J T, Lee J-K, Shahriar M S, Phan C, Yamamoto M
Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, USA.
Appl Opt. 2006 Aug 20;45(24):6148-53. doi: 10.1364/ao.45.006148.
We demonstrated a real-time shift-invariant VanderLugt correlator (VLC). The VLC was implemented with a 37 microm thick bis-triarylamine side-chain polymer matrix photorefractive (PR) polymer composite operating at 532 nm wavelength. Correlation selectivity was enhanced by real-time edge enhancement. The advantage of the VLC is that its architecture allows overcoming the PR material response speed. A correlator of this type enables a fast shift-invariant search of a large optical image database. A high degree of shift invariance in our correlator was possible because of the material thickness. The angular bandwidth of this material was measured experimentally in a degenerate four-wave mixing setup, and it was found to be in a very good agreement with the theory.
我们展示了一种实时平移不变的范德卢格特相关器（VLC）。该VLC是用一种厚度为37微米的双三芳基胺侧链聚合物基质光折变（PR）聚合物复合材料实现的，工作波长为532纳米。通过实时边缘增强提高了相关选择性。VLC的优点在于其架构能够克服PR材料的响应速度。这种类型的相关器能够对大型光学图像数据库进行快速的平移不变搜索。由于材料厚度的原因，我们的相关器实现了高度的平移不变性。在简并四波混频装置中对该材料的角带宽进行了实验测量，发现与理论结果非常吻合。
