As2S8平面波导：退火-光照-退火循环作用下折射率的变化及光传输特性

蒸发沉积态的非晶半导体As2S8薄膜在退火-饱和光照-退火循环处理下,其折射率变化存在可逆。而对于在退火-非饱和光照-退火的连续处理,发现As2S8薄膜折射率先增加达到最大值,然后在退火作用下才出现可逆。退火处理引起S-S键态变化,导致非晶半导体As2S8薄膜结构达到一定稳定状态,伴随着薄膜厚度的减小。As2S8平面波导在130C 温度退火,然饱和光照,又经过130C 温度退火处理后,显示出约为0.27 dB/cm低的传输损耗,在波长632.8 nm导模下有良好的光传输性能。     

BK7玻璃保护层掺钕磷酸盐玻璃波导特性

实验研究了基于KNO3稀释AgNO3混合熔盐离子交换法制备的镀有BK7玻璃保护层的N31型掺钕磷酸玻璃平面波导。采用棱镜耦合技术测试了其波导的有效折射率,应用IWBK方法拟合了其折射率分布。实验结果表明:在一定的扩散时间(5～7h)和交换温度(360～380℃)范围内,KNO3与AgNO3混合熔盐比对波导制备的影响起主导作用,引起的表面折射率的变化可达到0.025;BK7玻璃保护层对热离子交换掺钕磷酸盐玻璃表面起到了很好的保护作用,获得了良好的导模传输特性,其光传输损耗约为0.9dB/cm。     

As_2S_8 planar waveguide:refractive index changes following an annealing and irradiation and annealing cycle,and light propagation features

The refractive index of as-evaporated amorphous semiconductor As₂S₈ film upon an annealing and saturation irradiation and annealing cycle is reversible.Upon successive treatment with annealing and non-saturation irradiation and further annealing,the refractive index of the as-evaporated amorphous semiconductor As₂S₈ film reaches a maximum value and then its reversibility occurs upon annealing.The annealing of the amorphous semiconductor As₂S₈ films results in the stabilization of the structure through changes of the S-S bonds in the nearest environment,accompanied by a decrease of film thickness.The As₂S₈ planar waveguide after annealing（130℃） and saturation irradiation and annealing（130℃） shows a good propagation characteristic with ca.0.27 dB/cm low propagation loss of the 632.8 nm guided mode.