电子束蒸镀H4膜工艺及其在808nm激光器腔面膜上的应用

Process Investigation of H4 Thin Film Prepared by Electron Beam Evaporation and Application on Laser Diodes Cavity Coatings

采用离子辅助电子束蒸镀H4(H4是两种激光损伤阈值较高的材料氧化钛和氧化镧化合而成,分子式LaTiO3)薄膜。研究了氧气压力和基底温度对薄膜的光学性能的影响。实验发现,随着基底温度升高,H4膜的折射率n明显增加,基底温度为100℃时,n808 nm=2.14;随着氧气压力的降低,H4膜的消光系数k变化很小,氧气压力为2.67×10-2Pa时,在400 nm以上波段几乎没有吸收,k400 nm=2×10-4。将优化的工艺参数用于808 nm激光器腔面高反射膜的镀制,并与采用氧化钛作为高反射膜镀制的激光器进行了比较,获得的激光输出特性略好于氧化钛的器件。因此,采用H4制备半导体激光器高反射膜是一种完全可行的新方法。

H4 thin films（which is a compound of titanium oxide and lanthanum oxide,chemical formula is LaTiO3） have been prepared by the ion assisted electron beam depositing technology.The effect of the substrate temperature and oxygen gas stress influencing on the optical characteristics of H4 thin films have been investigated.It is found that the refractive index n dramatically increases with the substrate temperature building-up,the value of n808 nm is 2.14 at 100 ℃ of the substrate temperature;the extinction coefficient k has changed little with the oxygen pressure reduction,the value of k400 nm is 2×10-4 at 2.67×10-2 Pa of the oxygen pressure.The optimized parameters are applied to the preparation of high reflection mirror of 808 nm lasers,compared with the lasers using titanium oxide as HR films,have obtained a little better laser output characteristics.Therefore,it is a kind of new method of completely feasible that H4 thin films are used as high reflectivity facet coatings of laser diodes.