Dual-rail nanobeam microfiber-coupled resonator

Abstract

A microfiber-coupled dual-rail nanobeam resonator is proposed and demonstrated. The dual-rail scheme is employed to encourage the overlap between the light emitter and the air mode. The one-dimensional resonant cavity is formed by contacting a curved microfiber with the dual-rail nanobeam. The finite width of the dual-rail nanobeam turns out to be advantageous for both out-coupling with the microfiber and broader tuning of resonant wavelength. By employing InGaAsP quantum well gain medium, a simple and robust reconfigurable laser is created. Experimentally we measure a quality factor of 11,000 and out-coupling efficiency of 30%. The spontaneous emission factor (β) of the nanobeam laser is measured to be 0.16. Computationally we identified a resonant cavity with a quality factor over 6 × 10(5) and out-coupling efficiency over 90%.

High-Q coupled resonances on a PhC waveguide using a tapered nanofiber with high coupling efficiency

“…However, the experimental quality factor (Q) of the cavity was limited to around 10 4 when the cavity was formed on an InGaAsP/InP quantum dot PhC waveguide. Numerical calculations revealed that the coupling efficiency could be as high as 90%, but the demonstrated efficiency was only a few percent with a 2D PhC waveguide [16] and 30% with a 1D nanobeam waveguide [17].…”