The polarization filtering property of ideal PhC waveguides can be reinstated in the practical PhC slab waveguide also which was compromised due to the newly originated index guided modes in PhC slab waveguides. This can be done by controlling the side wall corrugation of the guiding portion of the PhC waveguide. By doing so, the guided TE, TM, and continuum of bands can be decoupled with each other for a sufficient range of operating frequencies. This way a TM-pass efficient polarization filters has been shown using silicon PhC slab waveguide, which gives a maximum extinction ratio of ≈ 43 dB, insertion-loss -0.5 dB along with ≈ 100 dB nm bandwidth in merely 20 periods long structure.
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