Bragg Grating Theory

Bragg grating theory describes how periodic variations in the refractive index of an optical fiber reflect specific wavelengths of light. When light travels through the fiber, these regular changes cause certain wavelengths—matching twice the grating period divided by the refractive index—to constructively interfere and reflect back, while others pass through. This selectivity depends on factors like the grating's spacing and the light's wavelength. Bragg gratings are used for filtering specific signals, sensing strain or temperature, and stabilizing laser outputs, making them essential components in advanced optical systems.