No abstract

No abstract

No abstract

The guided-mode resonance phenomenon in curved grating structures was studied. By using finite-difference time-domain simulation in the cylindrical coordinate system, we investigated the dependence of the peak reflectivity and bandwidth of the resonance upon the curvature radius. We clarified that the reflectivity and bandwidth were similar to those of flat grating structures for a finite range of curvature. We also discussed the key factor that determines the performance of reflection.

A concentrically patterned photonic crystal mirror with polarization selectivity fabricated by the autocloning technique was used for the generation of radially and azimuthally polarized beams from an Nd:YAG laser cavity. By adopting the photonic crystal mirror as the output coupler of the cavity, both radially and azimuthally polarized beams were obtained with similar output power as that of an unpolarized beam generated by a conventional, non-polarization-selective output coupler.