建構於光子積體迴路技術並應用於頻率調變連續波光達系統的光引擎之開發(3/3)

In the recent years, the development of Lidar technologies is booming due to itsfancy applications in self-driving cars and unmanned vehicles. Now, lots of majorcar manufactures, big IT companies, and numerous star-up companies arededicated to this topic. Up to now, most of the commercial available Lidar systemis based on optical pulse at 905 nm wavelength, mechanical steering mirror,single-photon avalanche photodiode, and time-of-flight (ToF) technology.However, this kind of technology suffers the eye-safe issue when lots of cars arerunning Lidar system simultaneously. In addition, the size of this kind of Lidarmodule is usually bulky. In order to overcome the above-mentioned problems,we will demonstrate a frequency-modulated continuous-wave (FMCW) Lidarsystem and its novel core chip (optical engine) inside. In this FMCW lidar, we willpush the operating wavelengths to around 1.55 m. Such optical window attelecommunication wavelengths can minimize the absorption in the retinal ofpeople and we can realize our Lidar system based on the InP based photonicintegrated circuit (PIC) technology, which is well-developed for the fibercommunication industry. In addition, the PIC scheme can help us downscale thesize of Lidar system. However, the major problems in the nowadays PIC is itshuge Input/Output coupling loss (~10 dB) with outside environment. This is notacceptable for the self-driving car Lidar, which needs a capability in long rangedetection (>100 meter). In this project, we will have a hybrid integration for PIC,which is composed by DFB laser and phase-shifter array, with liquid crystal activelens. Based on such scheme, we can discard most of the lossy components inour PIC and realize 2-D scanning and 3-D imaging. Besides, we will demonstratea novel avalanche photodiode (APD) array, which can provide high responsivityand high saturation current in the receiver end. By use of such gadget, animproved signal-to-noise (S/N) ratio and longer ranging distance can beexpected