Optical Filters Utilizing Ion Implanted Bragg Gratings in SOI Waveguides

The refractive index modulation associated with the implantation of oxygen or silicon into waveguides formed in silicon-on-insulator (SOI) has been investigated to determine the feasibility of producing planar, implantation induced Bragg grating optical filters. A two-dimensional coupled mode theory-based simulation suggests that relatively short grating lengths, on the order of a thousand microns, can exhibit sufficient wavelength suppression, of >10 dB, using the implantation technique. Fabricated planar implanted slab-guided SOI waveguides demonstrated an extinction of -10 dB for TE modes and -6 dB for TM modes for the case of oxygen implantation. Extinctions of -5dB and -2 dB have been demonstrated with silicon implantation.