Open AccessSemiconductor disk laser in bi-frequency operation by laser ablation micromachining of a laser mirror
Author(s) -
Jonathan Woods,
Daniel J. Heath,
Jake Daykin,
Theo Chen Sverre,
Ben Keenlyside,
B. Mills,
I. Sagnes,
G. Beaudoin,
S. Blin,
A. Garnache,
A.C. Tropper,
Vasilis Apostolopoulos
Publication year - 2019
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.27.022316
Subject(s) - optics , laser , materials science , lasing threshold , distributed bragg reflector , distributed feedback laser , semiconductor laser theory , optoelectronics , disk laser , tunable laser , solid state laser , physics
We present bi-frequency continuous wave oscillation in a semiconductor disk laser through direct writing of loss-inducing patterns onto an intra-cavity high reflector mirror. The laser is a Vertical External Cavity Surface Emitting Laser which is optically pumped by up to 1.1 W of 808 nm light from a fibre coupled multi-mode diode laser, and oscillates on two Hermite-Gaussian spatial modes simultaneously, achieving wavelength separations between 0.2 nm and 5 nm around 995 nm. We use a Digital Micromirror Device (DMD) enabled laser ablation system to define spatially specific loss regions on a laser mirror by machining away the Bragg layers from the mirror surface. The ablated pattern is comprised of two orthogonal lines with the centermost region undamaged, and is positioned in the laser cavity so as to interact with the lasing mode, thereby promoting the simultaneous oscillation of the fundamental and a higher order spatial mode. We demonstrate bi-frequency oscillation over a range of mask gap sizes and pump powers.