Development of power-scaled tunable alexandrite lasers
File(s)
Author(s)
Tawy, Goronwy
Type
Thesis
Abstract
Alexandrite is a highly attractive laser source in the near-infrared owing to its broad
wavelength coverage of around 700-820nm and strong thermo-mechanical properties.
This makes it a suitable laser source for a number of applications including
remote sensing, biophotonics and quantum technologies.
Over the last ten years there has been considerable progress in the development of
red-diode-pumped Alexandrite lasers, however there remained to be a demonstration of multi-watt Alexandrite lasers with wavelength tuning in fundamental TEM00 transverse and single-longitudinal-mode (SLM) operation. The aim of this work is therefore to develop power-scaled Alexandrite lasers with wavelength tuning which will bring it closer to applications outside the laser laboratory.
A novel wavelength-tunable and dual wavelength Alexandrite laser is presented
with a continuous wavelength tuning range of 747-768nm using the crystal as both
the gain medium and wavelength tuning element.
For accurate laser cavity design a detailed study of pump-induced lensing in
Alexandrite lasers is performed. This includes the development of an analytical
theoretical model and direct wavefront measurement under both non-lasing and
lasing conditions. New insight into pump-induced lensing in Alexandrite is gained
and a combined thermal and population lens postulated.
Utilising this improved understanding, a record power of 8.6W is demonstrated
in diffraction-limited TEM00 mode. >1W over 730-805nm and >4W over 755-780nm narrow-linewidth wavelength tuning is achieved for the very first time from a red-diode-pumped Alexandrite laser. This power is higher than any other directly diode-pumped vibronic laser in the 700-820nm region.
SLM operation is demonstrated in two compact ring laser cavities with up to
1W of output power. Power scaled ring lasers up to the 5W-level are also presented
showing promising signs for >1W wavelength tunable SLM performance.
wavelength coverage of around 700-820nm and strong thermo-mechanical properties.
This makes it a suitable laser source for a number of applications including
remote sensing, biophotonics and quantum technologies.
Over the last ten years there has been considerable progress in the development of
red-diode-pumped Alexandrite lasers, however there remained to be a demonstration of multi-watt Alexandrite lasers with wavelength tuning in fundamental TEM00 transverse and single-longitudinal-mode (SLM) operation. The aim of this work is therefore to develop power-scaled Alexandrite lasers with wavelength tuning which will bring it closer to applications outside the laser laboratory.
A novel wavelength-tunable and dual wavelength Alexandrite laser is presented
with a continuous wavelength tuning range of 747-768nm using the crystal as both
the gain medium and wavelength tuning element.
For accurate laser cavity design a detailed study of pump-induced lensing in
Alexandrite lasers is performed. This includes the development of an analytical
theoretical model and direct wavefront measurement under both non-lasing and
lasing conditions. New insight into pump-induced lensing in Alexandrite is gained
and a combined thermal and population lens postulated.
Utilising this improved understanding, a record power of 8.6W is demonstrated
in diffraction-limited TEM00 mode. >1W over 730-805nm and >4W over 755-780nm narrow-linewidth wavelength tuning is achieved for the very first time from a red-diode-pumped Alexandrite laser. This power is higher than any other directly diode-pumped vibronic laser in the 700-820nm region.
SLM operation is demonstrated in two compact ring laser cavities with up to
1W of output power. Power scaled ring lasers up to the 5W-level are also presented
showing promising signs for >1W wavelength tunable SLM performance.
Version
Open Access
Date Issued
2021-04
Date Awarded
2021-07
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Damzen, Michael
Sponsor
Engineering and Physical Sciences Research Council
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)