Feature issue introduction: mid-infrared optical materials and their device applications

Abstract

The mid-infrared (mid-IR, 2 to 10 μm) is a technologically important spectral regime for sensing, imaging, and communications. In the past few years, there has been a surge of interest in novel mid-IR optical materials as well as their device implementations to address the increasing demands from these applications. The 22 papers in this feature issue represent a diverse cross-section of the latest technological advances in this field, spanning mid-IR light generation, propagation, manipulation, and detection functions in free-space, fiber, and planar platforms. In terms of material systems, semiconductors, glasses, plasmonic metals, as well as nanostructures specifically engineered for the mid-IR band, are all extensively covered. We hope that the readers will enjoy the kaleidoscopic view of the burgeoning field of mid-IR optics and photonics through this feature issue.

Broadband Multi-Species Trace Gas Detection by Up-Converting Mid-Infrared Supercontinuum Light into the Near-Infrared

“…Khalil Eslami Jahromi, Qing Pan, Amir Khodabakhsh, Frans Harren Recent advancement in compact, stable, and broadband mid-infrared supercontinuum (SC) sources has provided attractive scientific and industrial applications in metrology, sensing, and communications [1]. The wide spectral coverage in the so-called molecular fingerprint region is the main advantage of such SC sources, opening up new opportunities for efficient multi-species trace gas detection at short time scale.…”

High power single crystal KTA optical parametric amplifier for efficient 1.4–3.5 µm mid-IR radiation generation

“…In recent decades, the field of laser technology has witnessed remarkable advancements, leading to the development of laser sources emitting in the mid-infrared (mid-IR) spectral range. The mid-IR region, typically covering wavelengths approximately from 2 to 10 µm [1], has gained significant attention for its unique properties and promising applications across various scientific and industrial domains. One particularly exciting development is the emergence of picosecond mid-IR laser sources, which offer a compelling combination of ultrafast pulse durations and the advantages of mid-IR radiation, such * Author to whom any correspondence should be addressed.…”

Double-pass optical parametric generator pumped by Yb thin-disk laser for efficient 1.4–2.9 µm mid-IR radiation generation

“…From the invention of the laser in 1960 [1] and immediate incorporation of laser light to other fields, such as medicine, a never-ending search for sources capable of generating light at new wavelengths, pulse lengths and repetition rates begun. Particularly interesting is the region of wavelengths from 2-10 µm [2], the so-called mid infrared (mid-IR), due to several interesting phenomena, such as the 'atmospheric window', and the molecular fingerprint region which enable the use of mid-IR sources in environmental, healthcare, and defense sensing applications. The maximum absorption peak of water around 3 µm must not be omitted due to its significant impact on the role of lasers in various fields of medicine, such as ophthalmology, dermatology, urology, and others.…”