Laser-diode-based joint transform correlator for fingerprint identification

A laser-diode-based joint transform correlator (JTC) is reported here for t he identification and discrimination of fingerprints. The system employs co mpact and inexpensive laser diodes as the light sources and a bacteriorhodo psin (BR) film in the Fourier plane, which can record the joint power spect rum without the need for expensive spatial light modulators or CCD cameras. The BR film also introduces nonlinearities in the Fourier plane which can improve JTC performance. In addition, real-time, all-optical programmable s patial filtering is demonstrated to improve the discrimination of the syste m. We present computer modeling and experimental results of this optical co rrelator, which shows excellent potential for the identification and discri mination of fingerprints. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)00701-1].