Open AccessDevelopment and evaluation of a hand-held fiber-optic Raman probe with an integrated autofocus unit
Author(s) -
Wei Yang,
Florian Knorr,
Jürgen Popp,
Iwan W. Schie
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.401207
Subject(s) - raman spectroscopy , autofocus , optics , signal (programming language) , lens (geology) , materials science , optical fiber , focus (optics) , sample (material) , computer science , fiber optic sensor , raman scattering , fiber , data acquisition , physics , composite material , thermodynamics , programming language , operating system
Current implementations of fiber-optic Raman spectroscopy probes are frequently based on non-contact probes with a fixed focus and thus and have to precisely maintain the probe-to-sample distance to ensure a sufficient signal collection. We propose and experimentally demonstrate a novel hand-held fiber-optic Raman probe design, which is based on a liquid lens autofocusing unit, combined with a distance sensor and an in-house developed algorithm to precisely determine the probe-to-sample distance. The reported probe significantly improves the signal stability even for hand-held operation, while reducing distance-dependent artifacts for the acquisition of Raman spectra and can improve the acquisition of Raman spectra in a variety of applications.