Two-dimensional optical filtering of 1-D signals

Real time self-pumped optical phase-conjugator based igner distribution processor for complex signals

Based on a combination of linear shift-invariant optical elements and a nonlinear photorefractive crystal serving as a self-pumped optical phase-conjugator, the real time optical generation of an auto- and cross- Wigner distribution for complex signals is demonstrated.

Generation of the Wigner distribution function of two-dimensional signals by a parallel optical processor

An optical system employing a reflective multipath scheme is implemented to generate a sectioned array of slices of the Wigner distribution function of a two-dimensional (2-D) signal. The optical system exhibits a parallel architecture, permitting the simultaneous generation and display of the N slices. Only a single transparency is needed, and no moving parts are required in the system. Experimental results on a few 2-D signals are presented.

Acousto-optic processors for real-time generation of time-frequency representations

Acousto-optic processors for calculating different two-dimensional (2-D) time-frequency representations for one dimensional temporal signals in real time are described. The various 2-D representations discussed in the literature, such as the Wigner distribution and the ambiguity function, are shown to be obtainable through minor variations in an acousto-optic processor consisting of two Bragg cells in a parallel configuration. Also obtained and discussed are two new time-frequency representations that, for amplitude-modulated signals, correspond to mean-frequency-selective correlation and Doppler-frequency-selective convolution. Experimental results are presented to highlight the special features of the different time-frequency representation.