Open AccessAmplitude modulation of femtosecond laser pulses in the megahertz range for frequency-multiplexed two-photon imaging
Author(s) -
Dmitri Tsyboulski,
Н. Н. Орлова,
Peter Saggau
Publication year - 2017
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.25.009435
Subject(s) - optics , femtosecond , laser , interferometry , two photon excitation microscopy , physics , phase modulation , amplitude modulation , amplitude , frequency modulation , materials science , radio frequency , fluorescence , phase noise , computer science , telecommunications
We present a frequency-multiplexed multi-site two-photon imaging method utilizing amplitude modulation of femtosecond laser pulses in the MHz range to tag each excitation beam and the corresponding fluorescence signals with specific frequencies. The frequency tags are generated with an interferometric scheme employing acousto-optic deflectors (AODs) to achieve precise spatial overlap of femtosecond laser pulses with periodically varying phase shift. Creating matching excitation beam patterns in each interferometer arm using multiple AOD driving frequencies, and subsequently overlapping these matching patterns, results in multiple encoded excitation beams with unique beat frequencies available for scanning. As a proof-of-concept, we demonstrate multiplexed two-photon image acquisition using test samples, and compare the performance of this approach to conventional two-photon laser scanning microscopy.