Sol-Gel and RF Sputtering Thin Film Coatings for Fiber Optic Sensor Applications

ABSTRACTThin film coating techniques appear to have many advantages over other techniques for immobilization and incorporation of chemical indicators to optical waveguides in developing dye based fiber optic chemical sensors. We have fabricated thin films of composites by using sol-gel and RF sputtering techniques. Different organic and inorganic indicators were immobilized in these films and incorporated into optical waveguides for sensor applications. A fiber optic pH sensor has been developed by introducing pH indicators into a silica matrix and coated as a thin film onto a porous glass fiber by a sol-gel technique. Also, a hydrogen gas fiber optic sensor has been developed by using a RF sputtered WO3/Pd coated porous optical fiber.