Low-dispersive phase-modulated rapid scanning interferometry

TL;DR

This paper introduces a low-dispersive phase modulation method for rapid scanning interferometry that avoids the disadvantages of acousto-optical modulators, achieving comparable sensitivity in Fourier transform spectroscopy.

Contribution

The paper presents a novel phase modulation scheme that replaces AOMs in interferometry, simplifying the setup while maintaining high sensitivity.

Findings

The new PM scheme performs comparably to AOPM in sensitivity.

Both schemes enable high-resolution Fourier transform spectroscopy.

The PM scheme reduces complexity and potential dispersion issues.

Abstract

Time-domain interferometry is an important principle in Fourier transform (FT) and nonlinear femto- to attosecond spectroscopy. To optimize the resolution and sensitivity of this approach, various interferometer stabilization schemes have been developed. Among them, acousto-optical phase modulation (AOPM) of the interferometer arms combined with phase-synchronous lock-in detection has proven as a particular sensitive technique. However, the acousto-optical modulators (AOMs), required for this technique, introduce several disadvantages. Here, we demonstrate an alternative phase modulation scheme which omits AOMs, termed PM scheme here. As a benchmark, we directly compare the performance between the PM and the AOPM scheme in a linear FT spectroscopy experiment and find comparable sensitivity in both approaches.