梯度折射率红外成像系统可在保持成像性能的基础上, 极大降低系统的尺寸、质量和成本, 有望推进红外成像系统向轻小型发展。然而, 目前没有可用的红外梯度折射率光学材料。本文基于65GeS2-25In2S3-10CsCl硫系玻璃, 利用梯度温度场热诱导析出轴向梯度分布的β-In2S3纳米晶体, 制得梯度折射率透明硫系微晶玻璃。结果表明: 析出的β-In2S3晶体为不同晶面取向纳米晶组成的多晶结构, 尺寸约为25 nm, 且晶体尺寸、数量与梯度温度场密切相关; 制得的梯度折射率硫系微晶玻璃仍保持良好的长波红外透过率, 且其10 μm处最大折射率差Δn达0.047。

Gradient refractive index infrared imaging system can greatly reduce the sizeweight and cost of system while maintaining imaging performancewhich is expected to advance the development of infrared imaging system towards lightweight and compactness. Howevercurrently available infrared gradient refractive index optical materials are not accessible. Based on 65GeS2-25In2S3-10CsCl chalcogenide glassa gradient temperature field was used to thermally induce the precipitation of axially gradient-distributed β-In2S3 nanocrystals to produce a gradient refractive index transparent chalcogenide glass-ceramics. The results show that the precipitated β-In2S3 crystals are polycrystalline structures composed of nanocrystals with different crystallographic orientationswith a size of about 25 nmand the size and number of crystals are closely related to gradient temperature field. The gradient refractive index chalcogenide glass-ceramics still maintain good transmission in long-wave infraredand their maximum refractive index difference Δn reaches 0.047 at 10 μm.