Two dimensional photonic crystal slab light emitters, light emitting arrays and chemical sensors

Two-dimensional photonic crystals (PC) can provide a universal platform for nanocavity optical resonators with high quality factor and small modal volumes and low-loss waveguides with unique dispersive properties. The small modal volume, high quality factor PC microcavities modify the density of states so that photons, due to enhancement of spontaneous emission rate, are preferentially emitted into microcavity resonant modes.; Optically excited PC membrane devices and their applications in multiwavelength low threshold lasers and ion sensors were demonstrated for the first time. Lasing from 3 resonant modes of a linear 3-missing defect microcavity was demonstrated with lasing thresholds 700nW, 2muW and 200muW respectively. It was observed that high quality (Q) factor resonant modes have low thresholds and high slope efficiency. Such multi-wavelength lasing capabilities of sub-micron cavities are very prospective for atmospheric remote sensing applications.; A photonic crystal microcavity based ion sensor is demonstrated for calcium (Ca2+) cations and perchlorate (ClO4-) anions. A 20nm shift in the position of the resonant peak was observed for a change of ClO4- ions in solution from 10 -6M to 10-3M while a 5nm shift was observed for Ca 2+ ions. The sensitivities of these devices are comparable to existing ion-selective sensors, but on a sub-micron length scale, and therefore leads to the prospect of novel on-chip integrated nano-photonic biochemical sensors and sensor arrays.; An air-bridge nano-contact technology was demonstrated that overcomes reduced injection efficiency problems typically associated with the realization of practical PC single microcavity and microcavity array devices. For the first time, an electrically injected PC device is demonstrated which injects carriers directly into the PC microcavity. Linewidths ∼ 0.95nm and 1.3nm were observed from whispering gallery modes and hexapole modes in a pedestal mounted membrane H2 PC microcavity. Observed linewidths are significantly narrower than corresponding linewidths in oxide clad membranes. Electrically injected photonic crystal microcavity arrays were demonstrated for the first time with 108 H2 microcavities, 37 H5 microcavities and 19 H7 microcavities using air bridge nano-interconnects. Significantly higher power was obtained from microcavity arrays than from single microcavities, while preserving the resonance characteristics of a single cavity.