多层介质膜红外空芯光纤的传输特性

TRANSMISSION CHARACTERISTICS OF INFRARED HOLLOW FIBERS WITH MULTILAYERED DIELECTRIC INNER-COATINGS

提出了一种计算多层介质膜空芯光纤损耗谱特性的方法,理论分析了介质—金属膜结构红外空芯光纤的传输损耗特性.将各层膜的厚度、材料色散和表面粗糙度等特性引入理论计算后,根据实测损耗谱估算了每层介质膜厚度.通过比较实测和理论计算损耗谱,调整优化了工艺参数.采用液相镀膜法,制作了在中红外波长带有低损耗特性的Ag/SiO2/AgI/SiO2三层介质膜结构空芯光纤.

A theoretical method for calculating the loss spectrum of the hollow fiber inner-coated with multi-dielectric-layer and silver layer was proposed. The transmission loss characteristics of infrared hollow fibers were analyzed theoretically. The film thickness for each dielectric layer was estimated according to the measured loss spectra by introducing the film thickness, material dispersion, and surface roughness into the theoretical calculation. The fabrication parameters of liquidphase coating and iodization process for SiO2 and AgI film were adjusted by comparing the measured and the calculated loss spectra. A hollow fiber with Ag/SiO2/AgI/SiO2structure was fabricated and low-loss property was demonstrated in the midinfrared wavelength region.