Open AccessSynchronized subharmonic modulation in stimulated emission microscopy
Author(s) -
Santanu Das,
You Liang,
Seizo Tanaka,
Yasuyuki Ozeki,
Fu Jen Kao
Publication year - 2019
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.027159
Subject(s) - optics , laser , modulation (music) , frequency modulation , sapphire , noise (video) , synchronization (alternating current) , signal (programming language) , materials science , physics , optoelectronics , telecommunications , computer science , acoustics , bandwidth (computing) , channel (broadcasting) , artificial intelligence , image (mathematics) , programming language
In this work, we have demonstrated a stimulated emission (SE)-based pump-probe microscopy with subharmonic fast gate synchronization, which allows over an order of magnitude improvement in signal-to-noise ratio. Critically, the alternative way of modulation is implemented with the highest possible frequency that follows the lasers' repetition rate. Its working is based on a homemade frequency divider that divides the repetition frequency (76 MHz) of the Ti:sapphire (probe) laser to half of the repetition frequency, 38 MHz, which is used to synchronously drive the pump laser and to provide the reference signal for the ensuing lock-in detection. In this way, SE can be detected with sensitivity reaching the theoretical (shot noise) limits, with a much lower time constant (0.1 ms) for faster image acquisition.