Mixed films were produced by means of composite-multilayer method and co-evaporation method to obtain any specified refractive-index or stress of thin films. The refractive-index of mixed film with SiO
2-ZrO
2 was almost the same as the calculated value from Lorentz-Lorenz formula. Two-wavelength antireflection (AR) coatings with composite-multilayer method were produced for the first time by combining the mixed films with SiO
2-ZrO
2 and MgF
2 on fused-silica and BK-7 glass substrates. The laser damage threshold of this AR coating was measured to be 10_??_12 J/cm
2 at 1.064 μm (pulse-width τ
p=1 ns) and 10_??_11 J/cm
2 at 0.532 μm (τ
p=1 ns), respectively. Also, the relation between laser damage threshold and stress of thin films were examined by using the SiO
2-MgF
2 mixed film and high reflectance mirror produced by mixed film with SiO
2-MgF
2 and ZrO
2. As a result, it has become clear that the laser damage threshold with τ
p of less than 1 ns is not affected from stress of less than 3000 kgf/cm
2 on thin films.
抄録全体を表示