Open AccessLock-in detector for accelerated nonlinear imaging
Author(s) -
Torben L. Purz,
Steven T. Cundiff,
Eric W. Martin
Publication year - 2021
Publication title -
optics letters/optics index
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.432353
Subject(s) - optics , detector , nonlinear system , filter (signal processing) , dwell time , amplifier , noise reduction , ultrashort pulse , noise (video) , modulation (music) , pixel , physics , computer science , laser , bandwidth (computing) , acoustics , artificial intelligence , telecommunications , computer vision , medicine , clinical psychology , quantum mechanics , image (mathematics)
We show that accelerated nonlinear imaging, such as stimulated Raman scattering and pump-probe imaging, is enabled by an order of magnitude reduction of data acquisition time when replacing the exponentially-weighted-moving-average low-pass filter in a lock-in amplifier with a simple-moving-average filter. We show that this simple-moving-average (box) lock-in yields a superior signal-to-noise ratio and suppression of extraneous modulations with short pixel dwell times, if one condition for the relation between the lock-in time constant and modulation frequencies is met. Our results, both theoretical and experimental, indicate that for nonlinear imaging applications, the box lock-in significantly outperforms conventional lock-in detection. These results facilitate the application of ultrafast and nonlinear imaging as a new standard for material characterization.