Faraday optical isolator in the 9.2 $\mu$m range for QCL applications

TL;DR

This paper reports the development of a mid-infrared Faraday isolator using n-doped InSb, achieving high isolation and transmission at room temperature, suitable for quantum cascade laser applications.

Contribution

The paper introduces a novel InSb-based Faraday isolator design optimized for the 9.2 μm range with high isolation and transmission at room temperature.

Findings

Achieved approximately 30 dB isolation ratio.

Transmission over 80% at room temperature.

Design adaptable to 7.5-30 μm wavelength range.

Abstract

We have fabricated and characterized a n-doped InSb Faraday isolator in the mid-IR range (9.2 $\mu$m). A high isolation ratio of $\approx$30 dB with a transmission over 80% (polarizer losses not included) is obtained at room temperature. Further possible improvements are discussed. A similar design can be used to cover a wide wavelength range (lambda ~ 7.5-30 $\mu$m).