Electrochemical driven self-holding optical actuator: from materials to device concepts

在该方案的框架下，我们将开发一种新型的自持电化学驱动光驱动器。我们的主要目标是评估用于驱动器的有前途的材料，并证明我们的方法与硅光子学兼容。执行器的作用是控制光在光子芯片上的传输。驱动原理是基于覆盖硅波导选定区域的混合离子-电子导体(MIEC)材料。通过波导传播的光波受到与MIEC材料的近场耦合的影响。作为光调制器的基材，我们使用了电致变色材料V2O5和WO3。锂和氢都将作为可移动离子用于MIEC材料的插层。MIEC材料的离子含量可以通过电化学反应来改变。随着化学计量比的改变，光学性质，即折射率和消光系数，以及在底层波导中传播的光波的强度和相位也将被改变。为了验证利用MIEC材料作为光学驱动器的概念，将采用溅射沉积的方法制备固态多层膜系统。多层叠层的电化学性能使得能够通过施加的电压/电流来调整MIEC材料的离子含量，从而调整其光学性质。通过将驱动器系统集成在硅光子电路上来研究光调制能力。为此，多层叠层将被沉积在各种硅波导结构的明确区域中，这些结构以前是通过电子束光刻和反应离子刻蚀相结合的方式制造的。将实验所得的硅光波导-驱动器系统的光学特性与模拟进行了比较，以期通过多次迭代实验与模拟的比较，获得一种在设计和性能方面都达到最佳性能的驱动器材料系统。

In the framework of this proposal we will develop a novel self-holding electrochemically driven optical actuator. Our key goal is to evaluate promising materials used for the actuator and to show that our approach is compatible with silicon photonics. The purpose of the actuator is the control of light transmission on photonic chips. The actuation principle is based on mixed ionic-electronic conductor (MIEC) materials that cover selected areas of silicon waveguides. Light waves propagating through the wave guide are affected by near-field coupling to the MIEC material. As base material for the optical modulator we use the electrochromic materials V2O5 and WO3. Both lithium and hydrogen will be used as mobile ions for the intercalation of the MIEC material. The ion content of the MIEC material can be changed by electrochemical reactions. With this change in stoichiometry also the optical properties, i.e., the refractive index and the extinction coefficient and thus the intensity and phase of light waves propagating in the underlying waveguide will be modified. In order to prove the concept of using MIEC materials as optical actuators, solid-state multilayer systems will be fabricated by sputter deposition. The electrochemical performance of the multilayer stack enables to adjust the ion content of the MIEC material and thus its optical properties by the voltage/current applied. The optical modulation capability will be studied by integrating the actuator system on silicon photonic circuits. For this purpose, the multilayer stack will be deposited in well-defined areas of various silicon waveguide structures that were fabricated before by means of electron beam lithography in combination with reactive ion etching. The optical properties of the silicon waveguide-actuator system derived from our experiments are compared with simulations in order to obtain an actuator material system with optimized properties in terms of design and performance from the comparison between experiment and simulation after several iterations.