Polarization-Resolved Near- and Far-Field Radiation from Near-Infrared Tilted Fiber Bragg Gratings

The radiation pattern of near-infrared light from 10° tilted fiber Bragg gratings is measured as a function of position along the grating, azimuthal direction, and input light polarization. An anomalous spatial periodicity in the radiation pattern is found and assigned to the presence of imperfect zero-order nulling and on the uncertainty in the exact alignment between the optical fiber and the phase mask used to form the grating. Furthermore, the intensity of the radiated light is correlated with the transmission spectrum of the tilted grating, showing narrowband spectral regions of increased and decreased radiation.