半导体光子学与技术, 2008, 14 (4): 274, 网络出版: 2011-08-19
Simulation of Tunable Power Multimode Interference Couplers with Deep Rib Structure
Simulation of Tunable Power Multimode Interference Couplers with Deep Rib Structure
integrated optics multimode interference coupler power tunable finite difference beam propagation method three dimensional
摘要
Abstract
The multimode interference (MMI) couplers, which operate at 1. 55 microns in deep rib InGaAsP/InP waveguide with large lateral confinement and tunable power splitting ratios, are of high interest in integrated optics. The gold contacts are applied on the top of waveguides where tuning is desired and the plasma effect will lead to negative refractive index change. The three-dimensional (3D) finite difference beam propagation method(FD-BPM) is used to model the tunable MMI couplers. The length of a 2×2 overlap-MMI is determined by FD-BPM, so the longitudinal position of tuning spots is obtained. The position of gold contacts with two types, the edge-pads or center-pad, are also determined. In our design, the length of MMI is 180 microns. If the width of pads is 50 microns and the refractive index is tuned from 0 to -0.027, the power ratio is tuned from 50∶50 to the maximum 88.5∶11.4. For deep rib structure, the effective index(EI) method can not be used to simplify the 3D waveguide to plane waveguide because of its lower precision, and so the direct 3D FD-BPM simulation is necessary for the design of 3D MMI couplers.
YAN Chao-jun, ZHAO Wen-bo. Simulation of Tunable Power Multimode Interference Couplers with Deep Rib Structure[J]. 半导体光子学与技术, 2008, 14(4): 274. YAN Chao-jun, ZHAO Wen-bo. Simulation of Tunable Power Multimode Interference Couplers with Deep Rib Structure[J]. Semiconductor Photonics and Technology, 2008, 14(4): 274.