Open AccessModelling and measurement of thermal stress-induced depolarisation in high energy, high repetition rate diode-pumped Yb:YAG lasers
Author(s) -
Mariastefania De Vido,
Paul Mason,
M. Fitton,
Rupert W. Eardley,
Gary Quinn,
Danielle Clarke,
Klaus Ertel,
Thomas Butcher,
P. J. Phillips,
Saumyabrata Banerjee,
Joanna Smith,
Jacob Spear,
Chris Edwards,
John Collier
Publication year - 2021
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.417152
Subject(s) - optics , materials science , laser , diode , amplifier , depolarization , stress (linguistics) , birefringence , laser pumping , thermal , optoelectronics , physics , medicine , linguistics , philosophy , cmos , meteorology , endocrinology
In this paper, we present a model to predict thermal stress-induced birefringence in high energy, high repetition rate diode-pumped Yb:YAG lasers. The model calculates thermal depolarisation as a function of gain medium geometry, pump power, cooling parameters, and input polarisation state. We show that model predictions are in good agreement with experimental observations carried out on a DiPOLE 100 J, 10 Hz laser amplifier. We show that single-pass depolarisation strongly depends on input polarisation state and pumping parameters. In the absence of any depolarisation compensation scheme, depolarisation varies over a range between 5% and 40%. The strong dependence of thermal stress-induced depolarisation on input polarisation indicates that, in the case of multipass amplifiers, the use of waveplates after every pass can reduce depolarisation losses significantly. We expect that this study will assist in the design and optimisation of Yb:YAG lasers.