Crossed Bragg cell processors

Abstract

In optical signal processing applications, two Bragg cells are sometimes crossed at an angle to display a correlation function in space. In this paper we show how the angle can be adjusted to control the scale of the correlation function. For signal acquisition, the received signal and the reference signal must be synchronized electronically. If the reference signal is time-reversed, the crossed cell geometry displays the correlation function in both space and time so that the optical system indicates the time at which the signals are synchronized. If the reference signal has a clock rate difference relative to the received signal, the correlation function still exists in both space and time but with the additional advantage that acquisition can be obtained without the need to time-reverse the reference signal.