COUPLING CHARACTERISTICS OF CLADDING MODES IN TILTED OPTICAL-FIBER BRAGG GRATINGS

We have studied both theoretically and experimentally the effect of gr ating tilting on the coupling between the fundamental core mode and th e cladding modes in an optical fiber Bragg grating. The coupling is sh own to be very sensitive on the tilting angle. It is also shown that t ilting angle has to be minimized in fibers with designs to suppress th e coupling between the fundamental core mode and the cladding modes. W e have also studied the single, strong loss peak accompanying the Brag g reflection peak in depressed-cladding fibers, thus showing a good ag reement between behavior that is measured and that is predicted theore tically. (C) 1998 Optical Society of America.