MPhys Physics with Theoretical Physics / Course details

Year of entry: 2024

Course unit details:
Frontiers of Photon Science

Course unit fact file
Unit code PHYS40611
Credit rating 10
Unit level Level 4
Teaching period(s) Semester 1
Available as a free choice unit? No

Overview

Frontiers of Photon Science

Aims

1. To gain an appreciation of the techniques of photon science.
In particular, to understand how:
• ultrafast laser pulses are produced, characterised and used
• nonlinear frequency conversion techniques can be used to change the wavelength of laser beams
• terahertz-frequency light is produced and detected
 
2. To illustrate the application of these techniques in scientific research
 
3. To provide a suitable introduction to students wishing to pursue postgraduate research in
photon science.

Learning outcomes

On completion successful students will be able to:
 
1. Describe the equipment and techniques used by photon scientists to produce and measure ultrafast laser pulses in the UV, visible, infra-red and terahertz spectral regions.
 
2. Analyse the optical response of nonlinear materials and explain how it can be optimised to enable the significant wavelength conversion of laser beams.
 
3. Describe terahertz radiation and its effect on materials
 
4. Explain quantitatively how these techniques can be used in scientific research to gain an understanding of electronic processes occurring on a sub-nanosecond time-scale.

Syllabus

1. Producing ultrafast laser pulses (2 lectures)
Mode-locking; dependence of pulse length and peak power on mode number; active and passive techniques. Oscillator-amplifier systems.
 
2. Nonlinear frequency conversion (8 lectures)
Nonlinear optical materials; modification of the wave-equation; three-wave coupling; phase-matching; second harmonic and sum-frequency generation; optical parametric amplifiers and oscillators
 
3. Advanced ultrafast laser diagnostics (2 lectures)
Single- and multiple-shot autocorrelators. Frequency-Resolved Optical Gating (FROG). Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPIDER).
 
4. Terahertz spectroscopy (8 lectures)
Pump-probe detection techniques. Methods of generating terahertz radiation (photoconductive antennas and optical rectification). Electro-optic sampling. Time-domain and frequency-domain techniques. Asynchronous optical sampling methods. Applications of terahertz spectroscopy (conductivity processes in semiconductors and biomolecules).
 
5. Ultrafast Transient Absorption Spectroscopy (2 lectures).
White light continuum generation. Application to carrier dynamics in quantum dots: state-filling effects; carrier cooling and recombination; carrier trapping; multiexciton effects including Auger recombination and biexciton binding energy. Mulitple exciton generation as means of exceeding the Shockley-Queisser limit to solar cell efficiency.

Assessment methods

Method Weight
Written exam 100%

Feedback methods

Feedback will be available on students’ solutions to problem sheets.

Recommended reading

Dexheimer, S. L., Terahertz Spectroscopy, (CRC Press)
Hannaford P., Femtosecond Laser Spectroscopy, (Springer Science)

Study hours

Scheduled activity hours
Assessment written exam 1.5
Lectures 22
Independent study hours
Independent study 76.5

Teaching staff

Staff member Role
Darren Graham Unit coordinator
David Binks Unit coordinator

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