Influence of electric field distribution on laser induced damage threshold and morphology of high reflectance optical coatings

• DOI: 10.1117/12.752902
• Publication Date: 2007-12-17T15:03:53Z
• Authors: G. Abromavicius; R. Buzelis; R. Drazdys; A. Melninkaitis; V. Sirutkaitis
• Keywords: Optical coating

Various investigations show that damage threshold of optical coatings by intense ultrashort laser pulses is closely related to the intensity electric field at layer interfaces. LIDT measurements high reflectance using femtosecond 800 nm wavelength are presented. ZrO₂, HfO₂ and Ta₂O₅ as refractive index materials for two sets experiments were chosen. Two different coating designs investigated: standard quarter-wavelength design with SiO₂ overcoat modified "E-field" non suppressed field. Damage sites studied AFM microscopes. Relation between distribution morphology was observed. The results demonstrate, suppressing interfaces enables increase almost twice if compared when pulses. However sensitive variations in thicknesses outer layers, so deposition process should be precisely controlled get improvement coatings.