Minimization of nonlinear acousto-optic Bragg cell intermodulation products

Abstract

The acoustooptic Bragg cell intermodulation products (IMPs) arising from multiple optical diffraction (dynamic IMPs) fundamentally limit Bragg-cell dynamic range. The IMPs arising from acoustic harmonic waves generated by the nonlinear elastic response of the Bragg cell crystalline lattice (elastic IMPs) may further limit dynamic range in Bragg cells operating at high frequencies or long time apertures. It is shown that the elastic IMPs can be minimized by increasing the Bragg-cell transducer length. The length can be increased without the attendant bandwidth loss using a phased array transducer. It is shown experimentally that this device is limited in dynamic range by the dynamic IMPs and thus exhibits the maximum spurious-free dynamic range possible.<>