Thermo-optical modeling of polymer fiber Bragg grating illuminated by light emitting diode

The development of a thermo-optical model of an illuminated polymer fiber Bragg grating (PFBG), combining use of the modified coupled-mode theory with thermal conduction theory and the modified transfer matrix method (TMM), is presented. This model is applied to the prediction of the thermo-optical behavior of an intrinsically heated and passively cooled PMMA fiber Bragg grating illuminated with a LED light source and operating over a range of ambient temperatures. Parametric influences on the thermo-optic characteristics and the predictive accuracy of several simplifications in the Bragg grating relations are also explored.