Thermal stability of photosensitive Bragg gratings in sputter-deposited germanosilicate glass

• Published in: Journal of non-crystalline solids Vol. 277; no. 2; pp. 114 - 126
• Main Authors: Potter, B.G, Simmons-Potter, K, Dunbar, T.D
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2000; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Infrared and raman spectra and scattering; Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity); Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Other nonmetallic inorganics; Physics; D110; P210; S160; G140; Raman spectra; Annealing; Inorganic compounds; ESR; Germanium silicates; Bragg grating; Color centers; Experimental study; Structure relaxation; Thermal stability; Photosensitive glass; Thin films; Absorption spectra
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/S0022-3093(00)00305-7

The thermal stability of photo-imprinted Bragg gratings formed in reactive-atmosphere, RF-magnetron sputtered germanosilicate thin films was evaluated in terms of point defect modifications observed during isochronal annealing. Optical and magnetic spectroscopies were utilized to evaluate structural relaxation in these sputtered glasses on both the local and medium-range size scale. Depending upon the substrate temperature used during deposition, significant structural rearrangement was found to occur with increasing post-deposition anneal temperature to 600°C. This resulted in changes in the photobleaching response of the material itself as the identity of optically active structural defects evolved. Based on a color center model for photosensitivity in these materials and measured changes in optical absorption with annealing, the thermal stability of a photo-imprinted Bragg grating was modeled. Good qualitative agreement with experiment was observed.