Lifetime prediction model for third-harmonic antireflection under high-repetition-rate multipulse laser irradiation

Area of Science:

• Materials Science
• Optical Engineering
• Laser Physics

Background:

• High-power lasers require durable optical coatings with predictable lifetimes.
• Assessing the laser-induced damage resistance of coatings is crucial for system reliability.

Purpose of the Study:

• To investigate the lifetime of Al2O3/SiO2 third-harmonic antireflection coatings under accelerated testing.
• To develop a predictive model for coating lifetime and damage thresholds at various repetition rates.

Main Methods:

• Accelerated testing of Al2O3/SiO2 coatings at repetition rates from 500 Hz to 3300 Hz.
• Analysis of damage evolution, threshold characteristics, and frequency effects.
• Development of a lifetime prediction model incorporating a frequency factor.

Main Results:

• The study established a lifetime prediction model for Al2O3/SiO2 antireflection coatings.
• The model accurately captures threshold variations with frequency and pulse count, showing strong agreement with experimental data.
• At 3300 Hz, the predicted threshold showed a deviation of only 0.88% from experimental results.

Conclusions:

• The developed model effectively bridges the gap between laboratory damage thresholds and real-world service lifetimes.
• This approach provides a reliable basis for assessing the longevity of optical coatings in high-power laser systems.
• The findings are critical for the reliability of future high-power space laser applications.