Fabrication and characterization of quasi two-dimensional photonic crystal structures with tunable optical properties

具有可变光学特性的光子晶体有望实现一类新的可调谐或可切换元件，并可能为大规模集成光电元件开辟新的领域。在本项目的框架内，将通过在AlGaAs/GaAs波导中填充液晶来制备可调谐的准二维光子晶体。电场可以改变液晶的光学性质。折射率变化可达0.2，这足以显著改变光子晶体的能带结构。这种新型光子晶体的基本性质将通过确定其透射和反射性质来表征。考虑到液晶的特殊材料性质，将结果与模拟结果进行比较。首先将进行可切换微谐振器中可变波导和光定位的可行性研究。这些基本功能是未来可调谐滤波器、微激光器或可切换波导等设备的基石。

Photonic crystals with variable optical properties are expected to allow the realization of a new class of tunable or switchable elements and could open a new field for large scale integrated optoelectronic components. In the frame of this project tunable quasi two-dimensional photonic crystals will be fabricated in AlGaAs/GaAs waveguides by filling photonic crystals with liquid crystals. The optical properties of liquid crystals can be modified by electric fields. Refractive index changes of up to 0.2 should be possible which is large enough to modify significantly the band structure of photonic crystals. The basic properties of this new class of photonic crystals will be characterized by determining the transmission and reflection properties. The results will be compared with simulations by taking into account the specific material properties of liquid crystals. First feasibility studies will be performed regarding variable waveguiding and light localization in switchable microresonators. These basic functions are building blocks for future devices like tunable filters and microlasers or switchable waveguides.