Projects for Final Year Undergraduate Students




Capture Unknown Microwave Frequency using Light

Identifying the instantaneous frequency of an unknown microwave signal in a wide frequency range is very important in the field of electronic warfare (EW). In an EW environment, capturing precisely the unknown microwave frequency is very challenging. Typically, the frequency of a radar signal can be varied in a range from several hundreds of MHz to several hundreds of GHz, but a signal receiver has to be operated in a very narrow frequency band to minimize the noise and interference. In the Optics Lab we have been developing optical modules for microwave frequency measurement, to take advantages of extremely broad bandwidth and immunity to electromagnetic interference offered by optics. In this project, performance of different optical modules will be evaluated. A selected optical module would be demonstrated for high-frequency microwave signal measurement. This project will involve both simulation and hands-on experimental work.



See Temperature Changes using an Optical Fibre Sensor

Temperature sensors are very important tools in both industrial and scientific applications. However, in very harsh environment with extremely high temperature and pressure, conventional sensors will fall short. Optical fibre sensors are made of silica glass. Therefore, they are very attractive for applications in harsh environment due to their proven advantages of immunity to electromagnetic interference and resistance to high temperature and chemical corrosion. The aim of this project is to learn the principle of optical fibre sensor and demonstrate temperature measurement using an optical fibre sensor.



Investigation of Microwave Frequency Multiplication Based on Optical Modulation

High-frequency and frequency-tunable microwave signals are useful in high-data rate communications and radar systems. Direct generation of high-frequency microwave signal is challenging. One promising solution is to multiply the frequency of a low-frequency “seed” signal. Modulating optical carrier with the “seed” microwave signal offers possibility to multiply the signal frequency. In this project, optical modulation and spectrum measurement will be implemented and frequency doubling will be demonstrated. Both simulation and hands-on experimental work will be involved.




Measure How Different Colours of Light Travel in Optical Fibre at Different Speeds

Optical fibre, which is mainly made of silica glass, is a perfect media to propagate light. For infrared light (with a wavelength around 1.5 micron), the propagation loss is extremely low, i.e., less than 0.2 dB per kilometre. Meanwhile, different colours of light travel at different speeds, due to the dispersion effect in optical fibres. Measuring dispersion property of fibreoptic devices is very important for systems that employ them. In this project, an optical setup based on external modulation and phase shift measurement will be designed and built to characterize the dispersion properties of common fibre-optic devices, such as optical fibres and fibre gratings. (Preliminary Labview knowledge is preferred but not a necessary).