Study on the influence factors of the characteristic of laser etalon with solid dielectric spacer-layer

For the laser etalon with solid dielectric spacer-layer, the effects of the stack numbers of reflection films on the reflection bandwidth, the thickness of substrate and the free spectral range are first studied by taking an example of laser etalon working at 1 064 nm. The results indicate that the bandwidth of the etalon decreases with the stack number increasing, and the free spectral range decreases with the thickness of substrate increasing. Then the effects of the deviation of substrate on the central wavelength and the transmittance of etalon are studied. The deviation of substrate thickness could be compensated by adjusting the working angle of the etalon through the numerical calculation. Further more, for the two typical coating structures such as H(LH)^m/Substrate/(HL)^m H and L(LH)^m/Substrate/(HL)^mL, the effects of the divergence angle of incident laser on the central wavelength, the half pass band width, the transmittance at central wavelength and the maximum transmittance are investigated. The results demonstrate that with the increasing of divergence angle, the central wavelength shifts to the shorter wavelength, and the half pass band width, the transmittance at central wavelength and the maximum transmittance show a downward tend. The performance of etalon with the coating structure of L(LH)^m/substrate/(HL)^mL is superior to that of H(LH)^m/substrate/(HL)^mH.