Narrow-band readout and compression of a single acousto-optic frequency comb using digitally enhanced heterodyne interferometry

Abstract

We present an acousto-optic frequency comb readout scheme synthesized from multiple intra-comb beat measurements using digitally enhanced heterodyne interferometry. The readout scheme enables a single acousto-optic frequency comb to achieve a compression factor, which normally requires a dual comb measurement scheme. We demonstrate an absorption measurement of the 2ν3 P10 H13C14N line obtaining a noise equivalent absorption sensitivity of 1.75 × 10−8cm−1Hz−1/2. Additionally we demonstrate the ability of the system to software-adjust the compression factor to access a wider optical bandwidth.