Chalcogenide Glass Microfibers for Mid-Infrared Optics

Abstract

With diameters close to the wavelength of the guided light, optical microfibers (MFs) can guide light with tight optical confinement, strong evanescent fields and manageable waveguide dispersion and have been widely investigated in the past decades for a variety of applications. Compared to silica MFs, which are ideal for working in visible and near-infrared regions, chalcogenide glass (ChG) MFs are promising for mid-infrared (mid-IR) optics, owing to their easy fabrication, broad-band transparency and high nonlinearity, and have been attracting increasing attention in applications ranging from near-field coupling and molecular sensing to nonlinear optics. Here, we review this emerging field, mainly based on its progress in the last decade. Starting from the high-temperature taper drawing technique for MF fabrication, we introduce basic mid-IR waveguiding properties of typical ChG MFs made of As2S3 and As2Se3. Then, we focus on ChG-MF-based passive optical devices, including optical couplers, resonators and gratings and active and nonlinear applications of ChG MFs for mid-IR Raman lasers, frequency combs and supercontinuum (SC) generation. MF-based spectroscopy and chemical/biological sensors are also introduced. Finally, we conclude the review with a brief summary and an outlook on future challenges and opportunities of ChG MFs.

Optical microfiber or nanofiber: a miniature fiber-optic platform for nanophotonics

“…Besides silica fibers, the electric heating method is also suitable for taper drawing MNFs from other types of glass fibers, especially soft glass with relatively low softening temperatures [see Fig. 5(b)] [55,147,148] . More recently, using a wide-zone electric heater, a parallel fabrication technique of silica MNFs has been reported [149] , which enables simultaneous drawing of multiple MNFs with almost identical geometries.…”

“…In the same year, Wang et al reported a broadband spectrum spanning from 1.4 to 7.2 μm in chalcogenide tapered fibers pumped in the normal dispersion regime [304] . The generated MIR supercontinuum sources have found important implications in the applications of molecular spectroscopy, MIR frequency comb, early cancer diagnosis, and remote sensing [147,305,306] .…”

Native Crystal Growth Revealed by a Joint Microscopy–Calorimetry Technique in (GeS2)0.1(Sb2S3)0.9 Thin Amorphous Films: A Critical Role of Internal Stress and Mechanical Defects

“…Note that chalcogenides are often used as optical elements (prisms, gratings, lenses, monochromators, or laser-tuned devices), (photoinduced) waveguides and optical fibers, optical amplifiers and lasers, photonic switches, thermal and hyperspectral imaging devices, temperature monitors, and chemical sensors in the infrared spectral region (due to their high transparency above ∼1 μm). In addition to their optical applications, the chalcogenide glasses are also known for being employed as optical and electrical memory materials, rewritable recording materials, solid electrolytes for batteries, sensitive electrochemical electrodes, ionic or superionic superconductors, transistors, or switches (owing to their semiconducting properties). − The second reason for the crystal growth rate studies in chalcogenide materials is the utilization of that information for controlled preparation of the crystalline phase. Such preparation can be either one-shot permanent formation of the chalcogenide ceramics and glass ceramics − or reversible, such as occurring in the state-of-the-art technologies based on the chalcogenide phase-change materials (nonvolatile memories, flexible displays, nanoscale switches, energy storage), − where the amorphous-to-crystalline transformation (induced by heating, lighting, or electrical means) represents a fundamental aspect of the device functionality.…”

Comprehensive Numerical Analysis of Temperature Sensitivity of Spherical Microresonators Based on Silica and Soft Glasses

“…Chalcogenide and tellurite glasses exhibit enormous Kerr and Raman nonlinearities [ 17 , 18 ]. This makes them an exceptional platform for nonlinear wave conversion applications in a wide parameter range, including supercontinuum generation [ 17 , 19 , 20 ], Raman soliton generation [ 21 ], continuous-wave Raman generation [ 22 ], generation of optical frequency combs [ 23 , 24 ], all-optical switching [ 25 ], ultrafast metrology [ 26 ], sensing and biosensing [ 27 ], etc. Although the nonlinear optical processes are not directly related to temperature sensing, thermo-optical effects are crucial for their practical realization and efficient control [ 23 ].…”