Coherently broadened, high-repetition-rate laser for stimulated Raman scattering-spectroscopic optical coherence tomography

• Type of Material: Article
• Authors: Francisco Robles, Emory University; Heiko Linnenbank, University of Stuttgart; Florian Moerz, University of Stuttgart; Patrick Ledwig, Emory University; Tobias Steinle, University of Stuttgart; Harald Giessen, University of Stuttgart
• Language: English
• Date: 2019-01-15
• Publisher: Optical Society of America
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2019 Optical Society of America.
• Final Published Version (URL): http://dx.doi.org/10.1364/OL.44.000291
• Title of Journal or Parent Work: Optics Letters
• ISSN: 0146-9592
• Volume: 44
• Issue: 2
• Start Page: 291
• End Page: 294
• Grant/Funding Information: National Cancer Institute (NCI) (R21CA223853); Burroughs Wellcome Fund (BWF) (CASI BWF1014540); ERC Advanced (COMPLEXPLAS); Deutsche Forschungsgemeinschaft (DFG) (SPP1391, SPP 1839, FOR730, GI 269/11-1); Bundesministerium für Bildung und Forschung (BMBF) (13N9048, 13N10146, PRINTOPTICS); Carl-Zeiss-Stiftung; Baden-Württemberg Stiftung (Spitzenforschung II); Georgia Institute of Technology.
• Keywords: FIBERS; Science & Technology; SUPERCONTINUUM GENERATION; Optics; Physical Sciences
• Research Categories: Physics, Optics; Engineering, Biomedical

Abstract

We present a novel light source specifically tailored for stimulated Raman scattering–spectroscopic optical coherence tomography (SRS-SOCT), which is, to the best of our knowledge, a novel molecular imaging method that combines the molecular sensitivity of SRS with the spatial and spectral multiplexing capabilities of SOCT. The novel laser consists of an 8 W, 450 fs Yb:KGW oscillator, with a repetition rate of 40 MHz, which delivers the Stokes beam for SRS-SOCT and also pumps and amplifies an optical parametric oscillator (OPO). The output of the amplified OPO is then frequency doubled and coherently broadened using a custom-made tapered fiber that generates bandwidth pulses >40 nm, compressible to <50 fs, with the average power over 150 mW, near the shot-noise limit above 250 kHz. The broadened and compressed pulse simultaneously serves as the pump beam and SOCT light source for SRS-SOCT. This light source is assessed for SRS-SOCT, and its implications for other imaging methods are discussed.