RESUMO
Silica-based one-dimensional photonic crystal (1D-PC) is fabricated by use of a high-spatial-frequency grating with input and output surfaces tilted with respect to its periodic direction. An incident beam is coupled with the first photonic band in the second Brillouin zone of the 1D-PC. The output beam angle changes 3 degrees with a wavelength change of 1%. A prototype of an ultrasmall demultiplexer is demonstrated by use of a silica slab waveguide with 1D-PC.
RESUMO
A compact and monolithic four-channel demultiplexer with 20-nm spacing was fabricated by use of a high-spatial-frequency transmission grating buried in a silica waveguide. The grating was successfully buried in a silica slab waveguide by overcladding by plasma-enhanced chemical-vapor deposition. The device's size was approximately 5.1 mm x 9.2 mm. The average insertion loss was 13 dB. The average cross talk was -15 dB for adjacent channels and -19 dB for nonadjacent channels. The polarization-dependent loss was estimated to be as low as 0.7 dB.
RESUMO
Binary gratings were fabricated with high first-order diffraction efficiency by conventional electron-beam drawing and subsequent inductive coupled-plasma dry etching upon the surfaces of SiO2 glass plates. The gratings were covered with a thin SiO2 film by plasma-enhanced chemical-vapor deposition without the grooves' being filled in. The buried gratings exhibited first-order diffraction efficiencies of 84% for transverse-electric and 87% for transverse-magnetic polarized light at a wavelength of 1.55 microm when the period and the depth were 1.5 and 2.8 microm, respectively.
