No abstract

We report one-dimensional (1-D) parabolic-beam photonic crystal (PhC) lasers in which the width of the PhC slab waveguide is parabolically tapered. A few high-Q resonant modes are confirmed in the vicinity of the tapered region where Gaussian-shaped photonic well is formed. These resonant modes originate from the dielectric PhC guided mode and overlap with the gain medium efficiently. It is also shown that the far-field radiation profile is closely associated with the symmetry of the structural perturbation.

One-dimensional surface-plasmonic nanobeam cavities are proposed as a means to confine surface plasmons to a subwavelength-scale mode volume, while maintaining a relatively high Q-factor. By bonding one-dimensional photonic-crystal nanobeam structures to a low-loss metallic substrate, a clear plasmonic TM bandgap can be formed. The introduction of a single-cell defect alongside the engineering of side-air-hole shifts to this plasmonic-crystal nanobeam provides subwavelength-scale plasmonic mode localization within the plasmonic TM bandgap. This suppresses radiation and scattering loss to render a maximum Q-factor of 413 and a modal volume of 3.67x10(-3) microm3 at room temperature. The possibility of further reduction in the intrinsic loss of the cavity is investigated by lowering the operating temperature and the Q-factor of 1.34x10(4) is predicted at a temperature of 20 K for the optimistic case.

Recent progress in the field of re-locatable photonic crystal resonators is discussed with a particular emphasis on the flexible scheme that employs highly-curved microfiber. In this scheme a spectrally-tunable high-quality-factor resonator can be defined repeatedly by physically moving a curved microfiber to a new position. When a curved microfiber is placed on top of a photonic crystal waveguide (or photonic crystal), a photonic well is newly created in the vicinity of the contact point. Inside of this photonic well, high-quality-factor resonant modes are generated at frequencies below the cutoff edge of the guided mode. The tapered microfiber is an integral part of a single mode optical fiber and efficient out-coupling is naturally obtained. The sub-nanometer spectral tuning capability that is available by changing the curvature of the microfiber is also an important characteristic and discussed. This spectrally-and spatiallyreconfigurable photonic crystal resonator is expected to be a potential platform for photonic crystal based single photon sources, which enables accurate spatial overlap and spectral overlap with a single quantum dot, together with straightforward photon out-coupling to the fiber with high efficiency.

No abstract

No abstract

No abstract

No abstract