Influence of SiO2 overcoat layer and electric field distribution on laser damage threshold and damage morphology of transport mirror coatings

2014 ◽  
Vol 319 ◽  
pp. 75-79 ◽  
Author(s):  
Meiping Zhu ◽  
Kui Yi ◽  
Dawei Li ◽  
Xiaofeng Liu ◽  
Hongji Qi ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Damage Threshold ◽  
Laser Damage Threshold ◽  
Laser Damage ◽  
Damage Morphology

scholarly journals Reflective Meta-Films with Anti-Damage Property via Field Distribution Manipulation

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 640
Author(s):  
Haichao Yu ◽  
Feng Tang ◽  
Jun Chen ◽  
Zao Yi ◽  
Xin Ye ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Incident Angle ◽  
Single Layer ◽  
Damage Threshold ◽  
Laser Damage Threshold ◽  
Laser Damage ◽  
Magnetic Dipoles ◽  
New Approach ◽  
Intense Light

The reflective optical multi-films with high damage thresholds are widely used in intense-light systems. Metasurfaces, which can manipulate light peculiarly, give a new approach to achieve highly reflective films by a single-layer configuration. In this study, reflective metasurfaces, composed of silicon nanoholes, are numerically investigated to achieve high damage thresholds. These nanoholes can confine the strongest electric field into the air zone, and, subsequently, the in-air electric field does not interact directly with silicon, attenuating the optothermal effect that causes damage. Firstly, the geometrical dependencies of silicon nanoholes’ reflectance and field distribution are investigated. Then, the excitation states of electric/magnetic dipoles in nanostructures are analyzed to explain the electromagnetic mechanism. Furthermore, the reflection dependences of the nanostructures on wavelength and incident angle are investigated. Finally, for a typical reflective meta-film, some optothermal simulations are conducted, in which a maximum laser density of 0.27 W/µm2 can be handled. The study provides an approach to improve the laser damage threshold of reflective nanofilms, which can be exploited in many intense-light applications.

scholarly journals Effect of Electric Field Regulation on Laser Damage of Composite Low-Dispersion Mirrors

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 65
Author(s):  
Yuhui Zhang ◽  
Yanzhi Wang ◽  
Hongbo He ◽  
Ruiyi Chen ◽  
Zhihao Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Theoretical Calculations ◽  
Protective Layer ◽  
Damage Threshold ◽  
Wide Bandgap ◽  
Material Interface ◽  
Wide Bandgap Material ◽  
Low Dispersion

Low dispersion mirrors are important because of their potential use in petawatt (PW) laser systems. The following two methods are known to increase the laser-induced damage threshold of low dispersion optical components: use of a wide-bandgap-material protective layer and control of electric field distribution. By controlling the electric field distribution of composite low-dispersion mirrors (CLDM), we shift the electric field peaks from the material interface into the wide-bandgap material. However, the damage threshold of modified-electric-field composite low dispersion mirror (E-CLDM) does not increase. Damage morphology shows that the initial damaged layer is Ta2O5. An immediate cause is the enhancement of the electric field in internal layers caused by surface electric field regulation. Theoretical calculations show that the damage threshold of CLDM or E-CLDM is determined by the competition results of bandgap and the electric field of layer materials. The CLDM with different materials or different protective layer periods can be optimally designed according to the electric field competition effect in the future.

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