Analysis of a fiber bragg grating writing process using low coherence interferometry and layer-peeling

We demonstrate accurate measurements ofthe longitudinal refractive index profile of a fiber Bragg grating (FBG). We measure the impulse response o f a FBG with a low-coherence interfrometer, calculate the complex spectrum from a Fourier transform of the interfrogram. and then apply a layer-peeling algorithm to find the index profile ofthe measured FBG. We use our results to calibrate and identify systematic errors in a scanning beam/dithered phase mask FBG writing system.