Strong sampled Bragg gratings for WDM applications

Strong sampled Bragg gratings are UV induced in planar low-loss silica waveguides. Using such gratings, multichannel wavelength-division-multiplexing (WDM) components can be manufactured with high precision. An ASE filter and multichannel add/drop multiplexer have been demonstrated and characterized using sampled gratings and optical circulators. The add/drop multiplexer exhibits an intraband crosstalk of -30 dB and an interband crosstalk of -20 dB when used with a 200-GHz channel spacing. Simulations using a matrix method are performed showing that the use of uniform sampled gratings is limited by interband crosstalk to channel spacings of around 100 GHz. Propagation losses induced by the amplitude modulated superstructure of sampled gratings are investigated.