High Quality-Factor 1-D-Suspended Photonic Crystal/Photonic Wire Silicon Waveguide Micro-Cavities

We have successfully fabricated and characterized suspended one-dimensional (1-D) photonic crystal/photonic wire (PhC/PhW) waveguide micro-cavities based on silicon-on-insulator (SOI). Our experiments have shown an enhancement of the resonance
Q
-factor from 18 700 to approximately 24 000, with normalized optical transmission of 70%, after removing the silica cladding underneath the silicon waveguide. We have also demonstrated that, for this condition, the resonance peak wavelength can be controlled by varying the length of the micro-cavity. These results were obtained by removing the silica cladding below the silicon waveguide to produce a ldquohangingrdquo wire waveguide. The three-dimensional (3-D) finite-difference time domain (FDTD) simulation approach used shows good agreement with measured results.