Welcome to the Photonics Group Page
Staff members: Prof. J. Donegan, Prof. J. Lunney, Prof. E. McCabe, Dr. L. Bradley, Dr. Vincent Weldon, Dr. P. Eastham.
The Photonics Group is based in the School of Physics, Trinity College Dublin. The group has laboratory and office space in the SNIAM, Hamilton, and CRANN buildings which are located at the east part of College as shown in the Contact section.
Photonics is the subject of the generation and the use of light. It is a relatively new field of research and is set to become a key technology for the 21st Century. It combines the power of laser light, optical fibers and waveguide structures and is set to revolutionise optical telecommunications and nanotechnology. At Trinity we are carrying out research into the concepts that underpin photonics, the materials of the future and novel applications. We focus on:
1. Nanophotonics: The interaction of quantum dot emitters and other nanoscale materials and the interaction of the emitters with microcavity resonators. We also study the mode structure of coupled microcavity resonators.
2. Optical Communications: Diode laser are key components in communications and in spectroscopy applications. We work on vernier-tunable semiconductor lasers with our patented stabilised Fabry Perot structure. We carry out many-body modelling of semiconductors aimed at improving their predictive capability for communications. We use diodes for optical sensing of environmental gases and study the effects of optical feedback on the performance of single mode lasers.
3. Laser and Plasma Applications: Pulsed lasers can be used to heat and vaporise all materials in a process called laser ablation. When the plume of ablated material is significantly ionised it is called a laser produced plasma (LPP). Laser ablation is widely used in laser machining, pulsed laser deposition (PLD) of thin films for research, laser induced breakdown spectroscopy (LIBS) for materials analysis and matrix assisted laser desorption/ionisation (MALDI). The group at TCD are doing research on the physics of laser ablation and PLD of functional oxide thin films and nanoparticles. We use both nanosecond and femtosecond lasers. We are also exploring how LPPs interact with magnetic fields and the potential of using a fast electrical discharge in LPP to heat and compress to plasma to make an extreme ultraviolet (EUV) source for photolithography.
4. Conical Diffraction: In 1832 in TCD William Rowan Hamilton predicted a new optical phenomenon called conical diffraction and shortly afterwards his colleague Humphrey Lloyd observed the effect for the first time. Internal conical diffraction arises when a narrow beam of light is directed along one the optical axes of a slab of biaxial crystal; the beam spreads out as a cone inside the crystal and emerges as a hollow cylindrical beam with unusual polarisation properties. At TCD we are using high quality biaxial crystals and laser light sources to explore new aspects of this curious optical effect. We have also used conical diffraction to develop new methods for optical trapping of microscopic objects and for the generation of radially polarised laser beams. More here...