ULTRA-NARROW BAND FIBEROPTIC BRAGG GRATING FILTERS FOR ATMOSPHERIC WATER VAPOR MEASUREMENTS

摘要

Experimental results using ultra-narrow band fiberoptic Bragg grating filters for DIAL atmospheric water vapor measurements are presented. Special fiber Bragg gratings were fabricated by Communications Research Center that had a 2.66-nm stop band centered at 946 nm; within this stop band were two transmission filter peaks: one peak at a 946.0003-nm water vapor absorption line and another peak at 945.9 nm, a region of no absorption. Experimental demonstration of pressure filter tuning was achieved and the performance characterization of several custom-made optical fiber Bragg grating filters was made. These measurements were compared with a theoretical model using a piecewise matrix form of the coupled-mode equation.