A monolithic frequency comb platform based on interband cascade lasers and detectors

TL;DR

This paper introduces a monolithic platform combining interband cascade lasers and detectors to generate frequency combs and perform dual-comb spectroscopy, advancing miniaturized mid-infrared sensing technology.

Contribution

It demonstrates self-starting ICL frequency combs and integrated room-temperature detectors, enabling compact, battery-powered dual-comb spectrometers.

Findings

ICLs can generate self-starting frequency combs with a splayed phase state.

Efficient room-temperature detectors operate up to several GHz bandwidth.

The platform supports integrated, miniaturized dual-comb spectroscopy.

Abstract

Optical frequency combs enable all-solid-state spectrometers that will trigger a breakthrough in miniaturization and on-chip integration of mid-infrared sensing technology. Interband cascade lasers (ICLs) are an ideal candidate for practical implementations due to their low power consumption and zero-bias detection functionality. Here, we demonstrate the generation of self-starting ICL frequency combs. We show that the gain is fast enough to respond to beating of the intracavity field, which hinders the formation of short pulses. Instead, the ICL operates in a comb state, where the phases of the fundamental intermode beatings are splayed over a range of $2\pi$. This state appears to be general to self-starting combs based on the inherent gain nonlinearity and minimizes oscillations of the population inversion. Using the same epi-layer material, we demonstrate efficient detector operation at room temperature up to several GHz bandwidth and thereby provide a complete and unmatched platform for monolithic and battery driven dual-comb spectroscopy.