Beam splitting characteristics of two-dimensional photonic crystals based on surface modulation

The light beam propagating characteristics of an open-type photonic crystal power splitter are investigated through modulating the structure’s surfaces. The light transmittance can be improved by optimizing the radii of air holes on the input surface. The propagating directions of the outgoing branch beams can be adjusted continuously by altering the period’s length of air holes on the output surface, and influence of the alteration of those air holes’ locations to the splitting phenomena is also studied. Furthermore, keeping the air holes’ arrangement on the output surface unchanged, the splitting behavior can also be adjusted by changing the arrangement of the air holes adjacent to the last row near the output surface. Comparing the light beam propagating behaviors along two opposite directions at normal incidence, it is shown that both the light transmittance and the light splitting characteristics can be significantly different.