Single-detector double-beam modulation for high-sensitivity infrared spectroscopy.

ABSTRACT: Balanced detection based on double beams is widely used to reduce common-mode noises, such as laser intensity fluctuation and irregular wavelength scanning, in absorption spectroscopy. However, employing an additional detector can increase the total system noise due to added non-negligible thermal noise of the detector, particularly with mid-infrared (IR) detectors. Herein, we demonstrate a new optical method based on double-beam modulation (DBM) that uses a single-element detector but keeps the advantage of double-beam balanced detection. The sample and reference path beams were modulated out-of-phase with each other at a high frequency, and their average and difference signals were measured by two lock-in amplifiers and converted into absorbance. DBM was coupled with our previously repor

SUBMITTER: Kim SM 

PROVIDER: S-EPMC10600177 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature