Open Access302 W quasi-continuous cascaded diamond Raman laser at 15 microns with large brightness enhancement
Author(s) -
Zhenxu Bai,
Robert J. Williams,
Ondřej Kitzler,
Soumya Sarang,
David J. Spence,
Richard P. Mildren
Publication year - 2018
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.26.019797
Subject(s) - brightness , optics , diamond , lasing threshold , laser , materials science , raman laser , duty cycle , optoelectronics , laser beam quality , raman spectroscopy , power (physics) , raman scattering , physics , laser beams , quantum mechanics , composite material
We report a second Stokes diamond Raman laser at 1.49 μm capable of high power and large-scale-factor brightness enhancement. Using a quasi-continuous 1.06 μm pump of power 823 W (0.85% duty cycle) and M 2 up to 6.4, a maximum output power of 302 W was obtained with an M 2 = 1.1 providing an overall brightness enhancement factor of 6.0. The pulse length of ~210 μs was selected to ensure operation was representative of steady-state continuous lasing conditions in the diamond bulk. Accompanying theoretical calculations indicate that even more strongly aberrated pumps may be used to efficiently generate high beam quality output and with higher brightness enhancement factors. This diamond-based beam conversion technique addresses needs for high brightness and efficient eye-safe sources using low-brightness 1 μm pumps and reveals a widely-applicable route to practical high brightness lasers of increased wavelength range.