基于多模干涉结构的可调控偏振分束器设计与分析

Design and Analysis of Controllable Polarization Beam Splitter Based on Multimode Interference Structure

可调控偏振分束器是一种新型光波导功能器件,对于提升集成光子系统性能或发展新应用有重要作用。采用多模干涉光波导结构,利用液晶的大双折射效应和高可调性能,提出了一种新型可调控偏振分束器。采用光束传输方法对偏振分束器的光学性能进行了模拟分析。结果表明,该偏振分束器不仅易于实现高的消光比和低的光损耗。对于横电(TE)模和横磁(TM)模偏振,其偏振消光比大于28.7dB,光损耗小于0.024dB,而且通过调控液晶晶轴的取向,可以动态调控TE模和TM模的输出端口。该器件结构简单,易于设计与制作,易于与其他光子器件进行集成,在集成光子系统中有着广阔的应用前景。

Controllable polarization beam splitter is a new type of optical waveguide functional device, which plays an important role in improving the performance of integrated photon system or developing new applications. A novel controllable polarization beam splitter is proposed by utilizing the large birefringence effect and high tunability of liquid crystal, in which the multimode interference optical waveguide structure is adopted. The optical performance of the polarization beam splitter is simulated and analyzed by the beam propagation method. The results show that, the polarization beam splitter is easy to achieve a high extinction ratio and a low optical loss. The polarization extinction ratio is over 28.7 dB and optical loss is less than 0.024 dB for both transverse electric (TE) wave and transverse magnetic (TM) wave polarizations. And the output ports of TE wave and TM wave can be dynamically controlled by adjusting the orientation of the crystal axis of liquid crystal. This device has several advantages such as simple structure, ease for design and manufacture, ease for integration with other photonic device, which has a wide potential application prospect in the photonic integrated circuits.