基于热膨胀效应的可调光功率分束器设计

Design of tunable optical power splitter based on thermal expansion effect

可调光功率分束器是集成光子系统中的重要功能器件,其光功率输出具有动态可调控特性,诸多光子系统对其有着广泛需求.本文基于空隙槽型Y分支波导结构,利用热膨胀效应,提出了一种新型可调光功率分束器实现方法,通过调控温度来改变分支处空隙槽的宽度,以实现其分支波导的光功率输出的动态变化.采用有限元方法,对其热膨胀形变和光学性能进行了模拟分析.其模拟结果表明,该器件能实现大范围光分束调控,且对波长和偏振态依赖性低;同时,该器件具有结构简单、易于设计和制作、易于调控等优点,这种新型器件在各种光子系统中具有重要应用前景.

The tunable optical power splitter is a key optical component used to dynamically control its optical power at its output ports, which has a wide application in many optical fields. A novel approach to controllable optical power splitter is proposed in this work, which is based on thermal expansion effect resulting in width variation of air gap at the branching point of Y-branch waveguide. The thermal expansion profile and the optical performance are simulated by using the finite element method （FEM）. The simulation results show that the tunable optical power splitter can exhibit good performance such as large dynamical range, low dependence of operation wavelength and its optical polarization. In addition, the proposed splitter with a simple structure can be easily designed, fabricated and controlled, which is very useful for potential application in integrated optical system.