During my recent trip to China I had the opportunity to meet with researchers in my field of integrated photonics. Through Chaotan Sima, an alumni of my research group in the Optoelectronics Research Centre, I was introduced to Professor Huilian Ma, of Zhejiang University’s Laboratory of Micro-Optic Gyroscopes in the school of Aeronautics and Astronautics. The research centre has approximately 40 research students and 10 professors. I had the pleasure of meeting Prof. Ma’s group, including my PhD student-counterpart Jianjie Zhang. I am extremely grateful for the kind and generous reception of my hosts, who made me discover Hangzhou food and helped me settle in after an eventful travel. Credit goes to them too for all the pictures in the post!
The visit was a great opportunity to learn about how photonics integrated circuits can be used as optical gyroscopes. Gyroscopes are used to stabilise position of navigation systems or automatic pilots independent of their movement of rotation. It is important for space applications, such as in satellites orbiting around the earth, where the ability to accurately determine position is of the utmost importance. Normally gyroscopes have moving (mechanical) parts, so can be delicate to package and send safely up to the space! The integration of these devices leads to more stable, smaller and scalable technologies.
Prof. Ma’s group at Zhejiang University is developing integrated optical gyroscopes on chips the size of a large stamp. They design and test prototypes on a silica-(glass)-on-silicon platform. These devices must maintain a very high signal-to-noise ratio to be efficient sensors. A well-known problem for optical gyroscopes is that the signal can be degraded by imperfect polarisations of the laser source used with these systems. In Southampton I had been researching ways to create on-chip polarisation filters compatible with silica technology, which could improve the performance of these devices. In the months leading up to this trip I had received some prototypes to test the suitability of the Southampton Direct UV Writing laser system to make polarizing filters using tilted gratings in waveguides, using the fabrication techniques I’ve discussed previously. The visit gave me the opportunity to present the work I’ve conducted to date and understand the testing methods. It’s been extremely worthwhile discussing the project directly with the people involved, and I’m looking forward to further experimental work that will arise from these discussions.
