Open AccessHigh-energy pulsed Raman fiber laser for biological tissue coagulation
Author(s) -
Hyoung Won Baac,
Néstor Uribe-Patarroyo,
Brett E. Bouma
Publication year - 2014
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.22.007113
Subject(s) - materials science , optics , fiber laser , microsecond , fiber bragg grating , laser , raman spectroscopy , amplified spontaneous emission , raman scattering , fiber , ytterbium , optoelectronics , wavelength , physics , composite material
We demonstrate a high-energy pulsed Raman fiber laser (RFL) with an emission wavelength of 1.44 μm, corresponding to an absorption peak of water. Microsecond pulses with >20 mJ/pulse and >40 W peak power were generated, well above the threshold for tissue coagulation and ablation. Here, we focus on the optical characterization and optimization of high-energy and high-power RFLs excited by an ytterbium fiber laser, comparing three configurations that use different Raman gain fibers, but all of which were prepared with a one-side opened, free-run mode without output mirrors. We show that the free-run configuration can generate sufficiently high energy without requiring a closed cavity design. Experimental RFL characteristics corresponded well with numerical simulations. We discuss the Stokes beam generation process in our system and loss mechanisms mainly associated with fiber Bragg gratings.