Infrared and Terahertz Radiation Detectors Based on Opto-Acoustic Converters (a Review)

Abstract

Classic opto-acoustic detectors are popular for a number of scientific and applied uses, such as measuring weak fluxes of optical radiation in the IR and THz ranges, quantitative and qualitative analysis of gas mixtures, and studying the absorption spectra of gases and vapors. The review considers the purpose, design and evolution of the basic structural elements of classic opto-acoustic detectors. We analyze the prospects of using single-layer graphene as the most promising material for membranes. The significant increase in sensitivity is due to the exceptionally high elasticity of graphene combined with its high mechanical strength. It has been shown that using a flexible single-layer graphene membrane reduces the acoustic and vibration noise susceptibility of opto-acoustic detectors by more than three orders of magnitude with no protection against vibration. Since the graphene membrane retains high elasticity at helium temperatures, the operating range of the opto-acoustic detector can be expanded from 320 K to helium temperatures, which provides the theoretically maximum threshold sensitivity by reducing noise and opens up the possibility of using opto-acoustic detectors for astrophysical and cosmological problems. We consider capacitive, optical, tunnel and cantilever detectors of microstrains of a flexible membrane. It is shown that achieving the maximum metrological characteristics of an opto-acoustic detector is possible by combining the unique capabilities of two inventions: a single-layer graphene membrane and a tunnel microstrain detector.