A new organic-inorganic hybrid material, which shows photo-induced reduction of refractive index as well as volume contraction, is prepared using a sol-gel method. This material is coated on a Si substrate by spin-coating to manufacture film. After irradiated by ultraviolet (UV) light with a deuterium lamp for 5 h, the thickness of film decreases largely by 55%, and the refractive index of film changes from 1.484 to 1.445 at 550 nm. The film's optical thickness exhibits an exponential change with the increasing irradiation time. Futhermore, the photo-patternning of the organic-inorganic hybrid film without any further process (wet etching and thermal curing) is performed utilizing the volume contraction on UV-light irradiation. This film has potential applications for fabrication of patterned filter array and apodizing filter by direct light writing, and also demonstrates good temperature stability and immunity to visible light exposure.
© 2010 Chinese Optics Letters
Jing Mao, Weidong Shen, Yi Yin, Yueguang Zhang, and Xu Liu, "Optical properties of highly photosensitive hybrid sol-gel films," Chin. Opt. Lett. 8, 435-438 (2010)