Date of Award
Master of Science in Electrical Engineering (MSEE)
Electrical, Computer, and Biomedical Engineering
The purpose of this study is to create an all digital solution for controlling the relatively cheap and small form-factor, all-semiconductor Distributed Feedback Lasers (DFBs). The objective is to generate a frequency sweep as linear as possible, which enables usage in applications like Coherent Optical Frequency Domain Reflectometry (C-OFDR). This is done utilize the input current dependency of the output frequency.
An Mach-Zehnder Interferometer (MZI) is used to measure the speed of frequency change. Next to that and a simple first order RC-filter, all components are implemented digitally using an Field Programmable Gate Array (FPGA) to allow for high adaptability as one of the many benefits of an all digital solution. XOR and Phase Frequency Detector (PFD) are evaluated as phase comparators.
Within this study, the XOR Phase Comparator (PC) together with a variable gain of the Loop Filter (LF) and a high capacitance RC-filter is found as the best solution.
Knipp, Stefan, "DIGITAL PHASE LOCK LOOP DESIGN FOR LINEARIZATION OF CHIRPED LASER" (2018). Open Access Master's Theses. Paper 1284.