The modern threat for electronic support measure (ESM) receivers are radars that use exotic wideband modulation waveforms for achieving higher resolution or reducing the probability of intercept. Existing ESM testbeds can receive both narrowband and wide-bandwidth modulations but can only detect the presence of narrowband signals. A wideband acousto-optic (AO) correlator (AOC) has been jointly developed by the Army Research Laboratory and Dynetics, Inc., under the ARPA TOPS program for insertion into an existing ESM testbed. The AO module is an in-line, time-integrating correlator architecture that offers a small, lightweight solution for detecting and analyzing inherently wide-bandwidth, spread-spectrum signals. The correlator processes 500 MHz of instantaneous bandwidth and offers enhanced detection capability of direct-sequence, phase-modulated chirps, and frequency-hopping signals. The ESM testbed, developed by the Intelligence and Electronic Warfare Directorate of the US Army Communications and Electronics Command, is currently being evaluated for integration into existing and future Army platforms. The AOC complements the existing ESM testbed and offers a wideband detection capability as described in this paper. The AOC insertion with the ESM testbed was demonstrated at the International Low Probability of Intercept Trials in Salisbury, australia. Performance results for the AOC against realistic LPI waveforms from this field test will be presented.