Experimental and theoretical progress on multiple wavelength laser induced damage of multilayer beam
splitters is reviewed. Test method for multiple lasers-induced damage thresholds were proposed based on
ISO 11254. Single and multiple laser-induced damage performance of the splitters, including damage
probabilities, damage thresholds and damage morphologies, were investigated respectively in order to
obtain better understanding of the damage mechanism at 355, 532 and 1064 nm. A judgment criterion for
coupling effect of different lasers in inducing damages was proposed and the detailed coupling efficiency
was also obtained. The small absorbing particle model and defect statistical model were put forward to
explain the experimental results. In addition, damage performance when the lasers arrived at the films with
nanosecond-delay in time was researched. Generally, the third harmonics play a key role in the damage
initiation.
In this paper, porous nanostructures on BK7 glass were manufactured by chemical treatment in order to obtain antireflection (AR) components with improved laser damage resistance. The damage-resistant properties of the samples with nearly 100% transmittances at three pulsed laser wavelength were investigated. The damage tests showed that the BK7 glass with AR nanostructures can achieve the LIDTs of 58J/cm2, 20 J/cm2 and 12 J/cm2 under the irradiation of 12ns 1064nm pulses, 10ns 532nm pulses and 8ns 355nm pulses, respectively. These values are much higher than those of AR coated glasses, but are almost the same level of un-etched substrate. The effect of structural properties on electric field distribution of porous surface was investigated by a three-dimensional (3D) finite difference time-domain (FDTD) model. The simulation results and the morphology of damage site on porous glass are compared to those of un-etched surface, and are discussed to reveal the possible damage mechanism. Finally, some possible solutions to improve the LIDT are proposed.
Coupling effect between 355 nm laser and 1064 nm laser in damage initiation and morphology formation are investigated on two different coatings prepared with Hf/SiO2 and HfO2/SiO2 respectively. It was found that materials had little influence on the couple effect. When extra 1064 nm pulse energy is low, 355 nm laser induced damage thresholds of both coatings increase because of laser conditioning and then when 1064 nm pulse energy is high enough, 355 nm LIDTs decreased. Damage morphologies are also studied to explore the damage mechanism at respective wavelength. For the entirely different electric field distribution, 355 nm laser induced damages are mainly from nanometer-sized absorbers at upper interfaces while initiators for 1064 nm laser locate at substrate-coating interface or substrate subsurface. Under simultaneous illumination, the sensitive defects are still the precursors, but the damages are more catastrophic compared with damages induced by 355 nm laser only and they also show representative damage characteristics induced by single laser, namely 355 nm laser induced small pits and 1064 nm laser induced large delamination. Further studies also show that delamination area grows with the increase of pit numbers induced by 355 nm laser at fixed 1064 nm laser fluence. A possible mechanism was proposed to interpret observed delamination area growth phenomenon.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.