Frequency Comb Assisted Diode Laser Spectroscopy for Measurement of Microcavity Dispersion

TL;DR

This paper introduces a simple broadband spectroscopy method combining frequency combs and diode lasers to accurately measure microcavity dispersion, aiding the development of optical frequency combs.

Contribution

It presents a novel, easy-to-use approach for broadband microresonator spectroscopy that enables precise dispersion measurements and microresonator dispersion tailoring.

Findings

Measured microresonator dispersion matches finite element simulations.

The method allows for effective dispersion tailoring via geometrical adjustments.

Excellent agreement between experimental and predicted dispersion values.

Abstract

While being invented for precision measurement of single atomic transitions, frequency combs have also become a versatile tool for broadband spectroscopy in the last years. In this paper we present a novel and simple approach for broadband spectroscopy, combining the accuracy of an optical fiber-laser-based frequency comb with the ease-of-use of a tunable external cavity diode laser. This scheme enables broadband and fast spectroscopy of microresonator modes and allows for precise measurements of their dispersion, which is an important precondition for broadband optical frequency comb generation that has recently been demonstrated in these devices. Moreover, we find excellent agreement of measured microresonator dispersion with predicted values from finite element simulations and we show that tailoring microresonator dispersion can be achieved by adjusting their geometrical properties.