Papers by Author: Yong Qing Huang

Abstract: Dithering particle swarm optimization (DPSO) algorithm is introduced into adaptive polarization stabilization in a 40 Gb/s optical communication system. The DPSO algorithm has the merits of rapid convergence to the global optimum, without being trapped in local sub-optima, and good robustness to noise. How to implement DPSO as a component of a control algorithm in adaptive polarization stabilization is described. Performance comparisons between PSO and DPSO were carried out theoretically and experimentally. It is demonstrated that fast changes of SOP can be successfully tracked using the DPSO algorithm.

Abstract: Subwavelength gratings (SWGs) that consist of net-grid structure are designed as infrared reflectors in this paper. By rigorous coupled wave approach (RCWA) and finite difference time domain (FDTD) method, we simulate its reflectivity which can reach 99.98% at 1.55μm while maintaining reflectivity higher than 99% across the 1.47-1.59μm wavelength range. We introduce SWG reflectors as the bottom mirrors in resonant cavity enhanced photodetectors (RCE PDs). RCE PD's quantum efficiency is increased to 95.7% at 1.55μm and the device has a significant size reduction compared with only using DBR bottom mirror.