波长和模式混合复用聚合物波导复用器

Over the next twenty years or so, the capacity of single-mode fiber in fiber networks should be increased to Pbit/s to meet the future demand of optical communication, which is much larger than the capacity limit of 100 Tbit/s. Combining mode-division multiplexing and wavelength-division multiplexing technologies provides a new method to boost the transmission capacities for the next generation communication systems, and it is pivotal to investigate the hybrid multiplexer. The wavelength and mode hybrid multiplexers based on silicon waveguides have many disadvantages, for example, it is sensitive to polarization states, and the coupling loss is high. The index difference of the polymer waveguide is close to that of fiber, so it can be used to realize optical devices that are insensitive to polarization states and have low coupling loss. This project proposes a novel wavelength and mode hybrid multiplexer, which is composed of a planar waveguide mode (de)multiplexer and a wavelength (de)multiplexer which is based on multimode interference waveguide. The two dimensions wavelength and mode are used to increase the number of data channels. The main research aspects will include: research on the structure of the device and its theoretical model , and the working mechanism; research on the quantitative relation between the parameters of the device and the optical characteristics, and optimization of the device parameters for design of the device that has low crosstalk (smaller than -15 dB), low loss (coupling loss smaller than 1 dB), and insensitive to polarization; fabricating the device with polymer materials and tuning the characteristics of the device taking advantage of its thermos-optic effect. This device has many advantages, such as design flexibility, easy for fabrication etc.

未来20年单根光纤传输容量要增加到Pbit/s量级才能满足未来通信的要求，它将远超过单模光纤的容量极限值100Tbit/s。模分复用与波分复用技术结合为下一代通信系统提供了可行的提高传输容量的方法，其中混合复用器的研制是关键。基于硅波导的波长和模式混合复用器有偏振相关、耦合损耗大等缺点。聚合物波导折射率差与光纤接近，可以实现偏振无关、低耦合损耗的光器件。本项目提出一个新颖的波长和模式混合复用器，它结合了平面波导模分复用器和多模干涉波导波分复用器，利用波长和模式2个维度来增加数据通道数。研究的主要内容包括：研究器件结构理论模型与工作机理；研究器件结构参数与光学特性的定量关系，优化获得低串扰（小于-15dB）、低损耗（耦合损耗小于1dB）、偏振不敏感器件设计；用聚合物材料制备器件，并利用其热光效应调控器件性能。器件具有设计灵活、易于制备等优点。

项目背景.目前波分复用系统的单模光纤带宽将很快被耗尽，波分复用技术提供的传输容量将不能满足未来通信容量需求。虽然可以通过指数增加光缆数目来满足通信发展要求，但是它会对成本和能耗造成浪费，而且它不是条可持续的技术方案。因此，用光纤中还没有被利用的自由度来提高光纤传输容量将对未来通信技术的发展起关键的作用。..主要研究内容.1．提出基于侧边抛磨六模光纤的模式选择耦合器（MSC），6个耦合器分别实现LP01,LP11,LP21,LP02, LP31,LP12 模式耦合。.2．侧边抛磨少模光纤表面等离子体共振生物传感器研究。提出一个基于少模光纤的表面等离子体共振生物传感器。传感器由侧边抛磨二模光纤及其表面沉积的金膜构成。.3．铌酸锂波导模式偏转研究。提出铌酸锂波导结合锯齿电极的结构，利用铌酸锂的电光效应实现模式偏转。.4．铌酸锂波导微环滤波器研究。提出一个基于光纤微环与铌酸锂波导光耦合的可调插分滤波器。滤波器振幅调制利用了铌酸锂波导的电光效应。.5．铌酸锂中电子-等离子体相互作用及其场分布相关调制研究。提出一个铌酸锂上镀金膜的结构，通过电子-等离子体相互作用实现电调表面等离子体共振。.6．基于铌酸锂波导模式电光偏转光开关研究。提出一个基于铌酸锂质子交换波导上微结构电极的1 × 2电光偏转光开关。..重要结果及关键数据.1. 制作的耦合器在1530nm-1600nm范围内有高耦合效率、低损耗及高模式纯度。耦合比大于81%，损耗小于1.8 dB，模式纯度大于81%。.2．侧边抛磨少模光纤表面等离子体共振生物传感器：在1.333 - 1.404范围内，传感器灵敏度为4903 nm/RIU，品因子为46.1 RIU−1。.3．铌酸锂波导模式偏转研究：器件能够在低电压下实现大角度偏转。80 μm 宽的波导在1064nm能够实现0.265 μm/V偏转。.4．铌酸锂波导微环滤波器研究：能够实现0.139 dB/V振幅调制。器件为微结构光纤与芯片光互联提供了新的方法。.5．铌酸锂中电子-等离子体相互作用及其场分布相关调制研究：强度调制及波长移动分别为~5.7 dB/V及~36.3 nm/V。调制效率与电极的场分布有关。器件可用于光互联、电场传感、表面等离子体电调等。.6．基于铌酸锂波导模式电光偏转光开关研究：在40 V电压下，二阶模式能在2个输出端口切换，在1530nm消光比为17.39