Composite acousto-optical modulation

TL;DR

This paper introduces a composite acousto-optical modulation scheme that enables wide-band, efficient laser modulation and high-contrast switching, with potential applications in ultrafast laser pulse shaping and quantum control.

Contribution

It presents a novel composite AOM scheme that achieves diffraction beyond the Bragg condition and high-contrast switching at RF limits, enabling advanced laser routing and pulse shaping.

Findings

Achieved diffraction across an octave of RF bandwidth.

Demonstrated efficient routing of mode-locked pulses at 400 MHz.

Enabled high-contrast switching using counter-propagating AOM pairs.

Abstract

We propose a composite acousto-optical modulation (AOM) scheme for wide-band, efficient modulation of CW and pulsed lasers. We show that by adjusting the amplitudes and phases of weakly-driven daughter AOMs, diffraction beyond the Bragg condition can be achieved with exceptional efficiencies. Furthermore, by imaging pairs of AOMs in a counter-propagating configuration, high contrast switching of output orders can be achieved at the driving radio frequency (rf) limit, thereby enabling efficient bidirectional routing of a synchronized mode-locked laser. Here we demonstrate a simplest example of such scheme with a double-AOM setup for efficient diffraction across an octave of rf bandwidth, and for routing a mode-locked pulse train with up to $f_{\rm rep}=400$~MHz repetition rate. We discuss extension of the composite scheme toward multi-path routing and time-domain multiplexing, so as to individually shape each pulses of ultrafast lasers for novel quantum control applications.