Three output port channel-drop filter based on photonic crystals

Enhanced light emission from Ge quantum dots in photonic crystal ring resonator

Light emitter based on Ge quantum dots embedded in photonic crystal ring resonator is designed and fabricated. Six sharp resonant peaks dominate the photoluminescence (PL) spectrum ranging from 1500 to 1600 nm at room temperature. The light emission enhancement is due to Purcell effect and high collection efficiency of the PCRR verified by calculated far-field patterns. The Purcell factor of the PCRR is estimated from enhancement factor and increased collection efficiency. The linewidth of the emission of a single Ge quantum dot is estimated from the Purcell factor.

High-quality-factor photonic crystal ring resonator

A design for enhancing the quality (Q) factor of a photonic crystal ring resonator (PCRR) is introduced. The highest Q factor based on simulations is 121,000. The analysis of momentum space distributions of the electric field profile for PCRR resonance shows that a high Q factor of a PCRR is attributed to the reduction of tangential k-vector component inside the leaky region. A high Q factor of 75,200 is experimentally demonstrated for a modified PCRR on a silicon-on-insulator wafer. The high-Q-factor PCRR demonstrated here will be beneficial for channel drop filters, lasers, sensors, and other applications.

High-quality photonic crystal heterostructures fabricated by a modified self-assembly method

High-quality three-dimensional photonic crystal (PC) heterostructures were fabricated using the modified self-assembly method, and their structural and optical properties were analyzed. Results suggest that the optical quality of heterostructures formed by depositing bigger particles on small ones is superior to that of heterostructures formed by stacking smaller particles on big ones, due to the rough interface effects in the latter structure. The roughness of the interface in the latter structure can be largely improved by introducing a thin two-dimensional planar defect layer into the PCs, and significant progress in the quality of the heterostructures is achieved. The important role of the thin planar defect layer in the quality of the heterostructures was also verified by numerical simulations.