Design of an effective energy storage cavity in two-dimensional photonic crystal slab

A design of a point-defect cavity in two-dimensional photonic crystal slab with both high Q factor and high transmission intensity has been achieved by adjusting the radii and position of lattice points in both parallel and perpendicular directions. Analysis shows that discrete resonant modes have been found in the 1550 wavelength range with Q factors up to 40,000. Moreover, the cavity was verified to subject to minor intensity decrease of 1.2 dB due to the introducing of external waveguide access. All these features make the cavity a very promising candidate for light transmission and detection in practical application. We also demonstrate the potential application of such a cavity being used as a sensitive index sensor with a high sensitivity of 400nm/refractive index unit.