14 July 1995 Interaction of laser radiation with coating defects
Author Affiliations +
The effect of absorbing inhomogeneities on the laser damage threshold at 1.06 micrometers is well known. We investigated the influence of laser irradiation below the damage threshold on the film absorption. Two regions of different defect denity were tested, a 'defect area' and a 'defect free area'. For those regions,the damage thresholds, and moreover, the thermal effects of irradiation below the damage threshold are different. First, the local distribution of absorption of the unirradiated 'defect free area' was measured. After the irradiation of this region, using a fluence short above the damage threshold, absorption was measured once more. A considerable decrease was observed. However, further pulses did not lead to a measureable change. The absorption increases distinctly after the 8th pulse for this sample, and the damage was registered after the next pulse. In contrast, irradiation of the 'defect area' with fluence below the damage threshold did not cause any changes of absorption. Nevertheless, after the 6th pulse the coating was damaged.
© (1995) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Bernhard Steiger, Bernhard Steiger, H. Brausse, H. Brausse, } "Interaction of laser radiation with coating defects", Proc. SPIE 2428, Laser-Induced Damage in Optical Materials: 1994, (14 July 1995); doi: 10.1117/12.213771; https://doi.org/10.1117/12.213771

Back to Top