R. Ulrich, Analysis of fiber gratings by external Bragg reflection Internal Communication , (1995) Link / Slides
Abstract: A dielectric grating in the core of a singlemode fiber, designed for internal Bragg reflection of wavelength LambdaB, may be analyzed by Bragg reflecting an external laser beam of a shorter wavelength (Lambda < LambdaB/n0), focused through the wall of the fiber onto its core (index n0). By scanning the probe beam along the fiber and measuring the reflected power and the angular deflection, the envelope of the index modulation Delta_n(z) and the chirp function g(z) of the fiber grating can be determined. This method is analyzed theoretically with respect to the resolutions attainable in z, Delta_n, and g for simple, nonslanted fiber gratings.
Home 
ulrich@tu-harburg.de