Shot-noise-limited emission from interband and quantum cascade lasers

TL;DR

This paper investigates the intensity noise of mid-infrared quantum cascade and interband cascade lasers, emphasizing their potential to operate at shot-noise-limited levels crucial for high-precision sensing and quantum optics applications.

Contribution

It provides a comprehensive comparison and detailed noise analysis of three room-temperature mid-infrared lasers, highlighting their noise characteristics and shot-noise-limited operation potential.

Findings

Quantum cascade lasers can achieve shot-noise-limited emission.

Interband cascade lasers show distinct noise behaviors from quantum cascade lasers.

The study offers insights for optimizing laser sources for quantum sensing applications.

Abstract

The intensity noise of a laser source represents one of the key factors limiting the ultimate sensitivity in laser-based systems for sensing and telecommunication. For advanced applications based on interferometry, the availability of a shot-noise-limited local oscillator is even more important for the effective feasibility of high-precision measurements. This is particularly crucial in quantum optics applications based on homodyne detection schemes to measure non-classical light states, such as squeezed states. This work deeply investigates and analyzes the intensity noise features of the most widely used mid-infrared semiconductor heterostructured lasers: quantum cascade and interband cascade lasers. For this purpose, a comprehensive comparison of three different continuous-wave lasers operating at room temperature around 4.5 {\mu}m wavelength is presented. First, a thorough electro-optical characterization is given, highlighting the differences and the shared common characteristics of the tested devices. Then, a detailed intensity noise analysis is reported, identifying their different noise operations with a particular reference to shot-noise-limited operations. Finally, some perspectives towards advanced applications are discussed.