A Defect-mediated-absorption-based Optical Power Monitor

Silicon photonics leads the trend of the modern technology. With the increasing integration of the photonic integrated circuits, it is sure to monitor the on-chip signals in real time. The power monitor can monitor the optical power inside a photonic integrated circuit for active control and error diagnosis. Specifically, there is a typical application in controlling the working states of the microring modulator due to its thermal sensitivity. So we find a solution of integrating both the modulator and the power monitor in one device to monitor the working states of the microring modulator.However, the bandgap energy of silicon that leads to the optical transparency at telecom wavelengths, limits optical power absorption and detection in the same regime. Firstly, we will focus on solving the detection problem in silicon and introduce different kinds of absorption mechanisms in power monitors and photodetectors. The ion-implanted defect-mediated-absorption-based optical power monitors will be discussed thoroughly. Secondly, this dissertation introduces a simulation process of building a defect-mediated monitor and analyzes the electrical properties of the device in detail. Because the defects in the depletion area will contribute the photocurrent, the distributions of carrier concentration, defect concentration, electric field intensity are drawn to analyze the performance of the optical power monitor. By optimizing the locations of the implantation windows and the dose of the implanted ion, the defects in the depletion area will change accordingly, and we will find out the reasons that affect the responsivities. Thirdly, we test the chip and analyze the different photocurrent curves of the devices with different locations of implantation windows and dose of the implanted ion. Also the optical loss is tested to analyze the reasons which affect the responsivity of the optical power monitor. What’s more, corrections of the simulation parameters are made according to the comparison between the test results and the simulation results.