Temperature dependence of absorptance in laser damage of metallic mirrors: II Vaporization and heating the vapor

For conventional metallic samples, agreement between experimental damage thresholds and three theoretical thresholds—for melting m, vaporizing ν, and heating to 2 eV—is fair (factor of ∼ 2 to ∼ 10). The previous scaling Itp∼tp1/2/A is valid in general, but It∼tp1/2 is valid for (I tp)m, (I tp)ν, and (I tp)2eV individually. Silver has the greatest theoretical threshold and figure of merit at 1.06 μm, but silver, copper, and gold have approximately equal figures of merit at 10.6 μm. Some clustering mechanism probably is involved in the isolated-spot damage observed in conventional samples.