Laser damage thresholds at short wavelengths.

Area of Science:

• Materials Science
• Optics
• Laser Physics

Background:

• Optical coatings and surfaces are crucial components in laser systems.
• Understanding their laser-induced damage thresholds (LIDT) is essential for system reliability and performance.
• Existing data on LIDT for diverse materials under various conditions is often fragmented.

Purpose of the Study:

• To systematically investigate and report the single-pulse laser damage thresholds.
• To evaluate a broad range of commercially available film coatings and prepared surfaces.
• To provide a comprehensive dataset for laser damage resistance across different wavelengths and pulse durations.

Main Methods:

• Laser damage testing was performed using single pulses at 532 nm, 355 nm, and 248 nm.
• For 532 nm and 355 nm, nanosecond pulses (0.7 ns) were generated via harmonic conversion of 1064 nm Nd:glass laser output.
• For 248 nm, longer pulses (20 ns) were generated using a KrF laser.

Main Results:

• A wide variation in laser damage thresholds was observed across different coatings and surfaces.
• Thresholds were found to be wavelength-dependent, with shorter wavelengths generally exhibiting lower thresholds.
• The influence of pulse duration was also evident, with longer pulses at 248 nm showing different damage characteristics.

Conclusions:

• The findings highlight the importance of material selection based on specific laser operating parameters (wavelength, pulse duration).
• This survey provides valuable data for engineers and researchers designing and utilizing high-power laser systems.
• Further research could explore damage mechanisms and optimize coating designs for enhanced laser damage resistance.