Paper
22 July 2016 Laser damage measurement of thick silica plates using a new laser injection scheme
D. Penninckx, R. Diaz, O. Bonville, R. Courchinoux, L. Lamaignère, J. Luce
Author Affiliations +
Proceedings Volume 9983, Pacific Rim Laser Damage 2016: Optical Materials for High-Power Lasers; 99830S (2016) https://doi.org/10.1117/12.2235748
Event: Pacific Rim Laser Damage 2016: Optical Materials for High Power Lasers, 2016, Yokohama, Japan
Abstract
Some silica plates of high power nanosecond lasers may be a few centimeter thick for instance because they should sustain vacuum. Measuring laser-induced damage thresholds at the output surface of these thick silica plates is a complex task because non-linear laser propagation effects may occur inside the plate which prevents knowing accurately the fluence at the output. Two non-linear effects have to be considered: stimulated Brillouin scattering (SBS) and Kerr effect. SBS is mainly driven by the spectral power density of the pulses: if the spectral power density is below a threshold, SBS is negligible. Thus, spectral broadening is required. Kerr effect depends on the instantaneous intensity. Hence, a smooth temporal shape without overshoots is required. However, both conditions (wide spectrum and no overshoots) are impossible to fulfill with standard lasers. As a matter of fact, an injected laser has a smooth temporal profile but is spectrally narrow. Without injection, the laser is multimode yielding a wide spectrum but a chaotic temporal profile. We solved the problem by phase-modulating a continuous-wave seeder of our laser (patent pending). The phasemodulation frequency is adjusted to a multiple of the inverse of the round-trip time of the laser cavity. The laser pulses have a wide spectrum to suppress SBS and do not exhibit temporal overshoots to reduce Kerr effects. During the presentation, we will show the features of the laser pulses and laser-induced damage measurements of thick silica plates using this scheme.
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
D. Penninckx, R. Diaz, O. Bonville, R. Courchinoux, L. Lamaignère, and J. Luce "Laser damage measurement of thick silica plates using a new laser injection scheme", Proc. SPIE 9983, Pacific Rim Laser Damage 2016: Optical Materials for High-Power Lasers, 99830S (22 July 2016); https://doi.org/10.1117/12.2235748
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Laser induced damage

Silica

Kerr effect

Continuous wave operation

Laser resonators

Q switched lasers

Q switching

Back to Top