Application of novel polarization handling elements into functional devices and optical systems

1.提高液晶偏振转换器的工作速度及其在半导体光放大增益补偿中的应用：为了提高我们研制的液晶可旋转波片的响应速度，我们同时进行了两个实验：一是提高器件的驱动电压，二是使用铁电型液晶材料。实验结果表明，这两种方法都可以成功地将响应速度提高到研究的9倍左右。2.将液晶功能器件集成到聚合物光波导中：通常情况下，聚合物等有机材料制成的光波导比硅基材料更容易制作，因为它们在整个制作过程中需要较低的温度。因此，通过将液晶与这些有机波导相结合，将有可能实现各种低成本的功能器件，如偏振转换器、开关、分支器件等。在这项工作中，我们发展了几种新颖的液晶集成技术到聚合物光波导中，其中包括在光波导芯的中间形成一个尺寸为10微米的腔体。根据初步实验结果，验证了这种聚合物集成液晶器件具有偏振转换功能。

1.Operation speeds improvement of the liquid crystal polarization converters and their application to the gain-compensation of semiconductor optical amplifiers :In order to improve the response speed of the liquid crystal rotatable waveplates which we have developed, two experimental trials were carried out simultaneously : one is to increase the driving voltage of the device, and the other is to use Ferroelectric-type LC material. As a result of experiment, both of them could successfully increase the response speed up to about 9 times compared to what has been studied. It was also found that the former type is superior to the latter type from the viewpoint of the operation stability.2.Integration of liquid crystal functional devices into polymer waveguides :In general, optical waveguides made of organic materials such as polymers are easier to fabricate than silica-based ones as they require lower temperature throughout the fabrication process. Therefore, by combining liquid crystals with these organic waveguides, it will be possible to realize various low-cost functional devices such as polarization converters, switches, branching devices, and so on. In this work, we have developed several novel LC integration techniques into the polymer waveguides, which includes the formation of a cavity with a scale of 10 mum in the middle of the core of the waveguide. According to the result of a preliminary experiment, it was verified that such polymer-integrated LC device could have polarization converting functions.