3rd year student projects

Analysis of waveguide modes using time-resolved THz near-field microscopy data

Project description:

One of the central challenges in research on THz waveguides is large transmission losses experienced by THz waves. Losses vary substantially for different modes of propagation and the mode structure provides intuitive understanding of loss characteristics [Ref] . The waveguide mode structure can be determined by a recently developed THz near-field microscopy method [Ref] . In combination with the time-resolved analysis this method allows to display propagating waves on a space-time map, in which the individual modes can be resolved. (Note: this project is ideal for a student who would like to apply skills in signal analysis (using MatLab) and learn about waveguides).

Automation of optical alignment using LabView

Project description:

In microscopy, orientation of the sample surface is critical for achieving high spatial resolution uniformly across the sample. The surface orientation therefore is adjusted in every sample. This project is focused on automation of sample surface orientation adjustment for scanning probe microscopy. The sample orientation and position can be controlled by programmable mechanical actuators and the feedback can be achieved through analysis of sample images captured by a camera. This project will involve developing of an algorithm for efficient orientation alignment and implementation of the alignment system using the LabView environment.

Short-time Fourier transforms in THz time-domain spectroscopy

Project description:

Spectroscopic analysis using broadband electro-magnetic pulses is widely applied in the THz part of the spectrum. The analysis is based on the Fourier representation of directly detected THz pulse waveforms. The Fourier analysis however does not reveal any time-domain information. In this project, alternative spectroscopic methods, short-time Fourier transform and Wavelet transform, will be applied to obtain dynamic information. The aim of this project is to investigate benefits of the dynamic analysis in studies of physical processes on the picosecond time scale.

Application of THz time-domain spectroscopy for detection of internal structure

Project description:

Terahertz waves, also known as T-rays, can be used to detect internal structure and chemical composition of visually opaque objects. THz spectroscopic analysis therefore provides a non-invasive detection method with potential applications in quality control, security and medicine. Signal analysis in this method however often involves modeling of effects of short pulse propagation in complex media. It is required to take into account possible multiple reflections in order to avoid spectroscopic artifacts. The aim of this project is to develop a numerical method for THz spectroscopy and apply it in studies of complex objects with internal structure.