The University of Southampton
University of Southampton Institutional Repository

Study of thermal lensing in Nd:YVO4 under intense diode-end-pumping

Study of thermal lensing in Nd:YVO4 under intense diode-end-pumping
Study of thermal lensing in Nd:YVO4 under intense diode-end-pumping
With its natural birefringence and high στf product, Nd:YVO4 is a popular choice as a lasing material for diode pumped solid-state lasers. The short absorption length for pump light at ~809nm relaxes the constraints on diode beam quality allowing tighter pump beam focusing and hence the use of relatively small laser mode sizes. However, in comparison to Nd:YAG it has poorer thermal properties, resulting in strong thermal-lensing, a knowledge of which is essential for optimum laser design. We present the results of a detailed study, considering the effect on thermal lensing in Nd:YVO4 of neodymium concentration, heat-sinking arrangement and laser configuration.
The thermal lens powers in end-pumped Nd:YVO4 were determined by measuring the induced phase difference as a function of transverse position using a Mach-Zehnder interferometer, figure 1. The interferometer was also equipped with a set of mirrors to form a stable non-collinear resonator for the Nd:YVO4 crystal to allow thermal-lensing to be investigated under lasing and non-lasing conditions.
Figure 1 The interferometer set-up and figure 2 example results.
Figure 2 shows the results obtained for 1% and 0.3% Nd-doped YVO4 crystals with cooled faces perpendicular to the c-axis and probe beam polarization parallel to the c-axis. The thermal lens power is ~5 times greater under non-lasing than for the lasing conditions for the 1% doped crystal, which we attribute mainly to additional heating from ETU, further compounded by reduction of thermal conductivity at higher temperature. The much smaller corresponding value for the 0.3% doped crystal indicates the potential benefits to (~2) be achieved with lower Nd concentrations. The results for the perpendicular heat-sinking direction and the orthogonal probe beam polarization, which suggest that thermally-induced stresses play a role in thermal lensing behaviour will also be presented. The results provided by this study allow formulation of a design strategy for further power-scaling of Nd:YVO4 lasers and amplifiers whilst maintaining good output beam quality.
Musgrave, I.O.
39045cdd-7992-4c9f-99b1-0827f1f236f7
Clarkson, W.A.
3b060f63-a303-4fa5-ad50-95f166df1ba2
Hanna, D.C.
3da5a5b4-71c2-4441-bb67-21f0d28a187d
Musgrave, I.O.
39045cdd-7992-4c9f-99b1-0827f1f236f7
Clarkson, W.A.
3b060f63-a303-4fa5-ad50-95f166df1ba2
Hanna, D.C.
3da5a5b4-71c2-4441-bb67-21f0d28a187d

Musgrave, I.O., Clarkson, W.A. and Hanna, D.C. (2001) Study of thermal lensing in Nd:YVO4 under intense diode-end-pumping. QEP-15. 03 - 06 Sep 2001.

Record type: Conference or Workshop Item (Poster)

Abstract

With its natural birefringence and high στf product, Nd:YVO4 is a popular choice as a lasing material for diode pumped solid-state lasers. The short absorption length for pump light at ~809nm relaxes the constraints on diode beam quality allowing tighter pump beam focusing and hence the use of relatively small laser mode sizes. However, in comparison to Nd:YAG it has poorer thermal properties, resulting in strong thermal-lensing, a knowledge of which is essential for optimum laser design. We present the results of a detailed study, considering the effect on thermal lensing in Nd:YVO4 of neodymium concentration, heat-sinking arrangement and laser configuration.
The thermal lens powers in end-pumped Nd:YVO4 were determined by measuring the induced phase difference as a function of transverse position using a Mach-Zehnder interferometer, figure 1. The interferometer was also equipped with a set of mirrors to form a stable non-collinear resonator for the Nd:YVO4 crystal to allow thermal-lensing to be investigated under lasing and non-lasing conditions.
Figure 1 The interferometer set-up and figure 2 example results.
Figure 2 shows the results obtained for 1% and 0.3% Nd-doped YVO4 crystals with cooled faces perpendicular to the c-axis and probe beam polarization parallel to the c-axis. The thermal lens power is ~5 times greater under non-lasing than for the lasing conditions for the 1% doped crystal, which we attribute mainly to additional heating from ETU, further compounded by reduction of thermal conductivity at higher temperature. The much smaller corresponding value for the 0.3% doped crystal indicates the potential benefits to (~2) be achieved with lower Nd concentrations. The results for the perpendicular heat-sinking direction and the orthogonal probe beam polarization, which suggest that thermally-induced stresses play a role in thermal lensing behaviour will also be presented. The results provided by this study allow formulation of a design strategy for further power-scaling of Nd:YVO4 lasers and amplifiers whilst maintaining good output beam quality.

Text
2249.pdf - Other
Download (67kB)

More information

e-pub ahead of print date: 2001
Venue - Dates: QEP-15, 2001-09-03 - 2001-09-06

Identifiers

Local EPrints ID: 17135
URI: https://eprints.soton.ac.uk/id/eprint/17135
PURE UUID: 8b58f6eb-8fc8-4024-bedb-1b011bd53cdb

Catalogue record

Date deposited: 16 Sep 2005
Last modified: 11 Jan 2018 17:31

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×