光热折变玻璃的研究进展

Research Progress on Photo-Thermo-Refractive Glass

光热折变玻璃是一种光敏硅酸盐玻璃,主成分为Na2O–ZnO–Al2O3–SiO2,并掺有Ag、Ce和F等成分,其折射率在紫外曝光并热处理后发生改变,具有在可见光以及红外光谱范围内损耗小,激光破坏阈值高,热稳定性好等特点,可用于制备衍射效率高,光谱选择性和角度选择性好的体Bragg光栅,可用于光谱窄化,相干耦合,谱合成等,在激光与光通信领域以及其他光学系统中有广阔的应用前景。分析了光热折变玻璃的折射率改变机制,讨论了光热折变玻璃的吸收特性,结构转变及激光破坏特性等光学特性。

Photo-thermo-refractive （PTR） glass is a photosensitive silicate glass. It is a Na20 - ZnO - A1203 - SiO2 glass doped with silver （Ag）, cerium （Ce）, and fluorine （F）, and exhibits a refractive index modulation after exposure to UV radiation followed by a thermal treatment. PTR glass demonstrates low absorption in the visible and near IR spectral regions, combined with high tolerance to elevated temperatures and laser radiation. Therefore, the volume Bragg gratings recorded in PTR glass have high diffraction efficiency at ill spatial frequencies in both reflecting and transmitting geometries and can be used in conversion of wide stripe laser diodes to emitters of single transverse mode radiation, coherent coupling of individual laser diodes, and for spectral combining of a number of beams with shifted wavelength, PTR glass is a new promising material to fabricate volume diffractive elements for lasers, optical communication, and other optical systems. In this paper, the refractive index decrement mechanism of PTR glass is analyzed and the absorption spectra, structure transformation and laser damage resistance of PTR glass is discussed.