Realization of geometrically apodized phase masks for the production of apodized fiber gratings by UV exposure

摘要

We describe the design methodology of geometric apodization and the fabrication of the apodized phase mask for UV-written fiber gratings. Concerning the two first diffraction orders used for UV exposure, the transmitted power is determined by the zero-order transmission, which is in turn determined by the variation of groove depth and ridge duty cycle. The simulated spectra for the zero-order output from a rectangular grating with a fixed ridge duty cycle shows that the position of the minimum zero-order transmission shifts with changing groove depth.