You can’t go very far without encountering a laser these days. They’re used to read Blu-Ray discs and DVDs, by laser printers and barcode scanners and for handy things like laser pointers. Lasers are used in surgery, for industrial cutting and welding, and even for entertaining light shows. Lasers are a part of everyday modern life.
The word ‘laser’ is an acronym for Light Amplification by Stimulated Emission of Radiation, and it’s used to describe coherent beams of light. Lasers can be tightly focused, enabling applications such as cutting and welding. Lasers can also have a very narrow spectrum of light, meaning they emit only one colour (wavelength), and can produce extremely short bursts of light that are a valuable research tool for scientists.
Our Central Laser Facility (CLF) is home to some very special lasers that are allowing researchers to make some very interesting discoveries.
Ultra is a specialist, flexible installation of lasers for advanced ultrafast dynamics studies in (bio-) molecular systems. Experts from the CLF set up complex experiments for visiting scientists and participate in the scientific research. Ultra is a ‘pump and probe’ system, meaning that pairs of ultrashort laser pulses are used to first stimulate a sample (initiate a reaction), and then perform spectroscopy to capture the results. Ultra uses a range of ultrafast light sources, allowing researchers to use multiple beams, in multiple colours and pulse lengths, to investigate life processes, such as protein-folding and photosynthesis in real time.
Using Ultra, one of our researchers (Professor Pavel Matousek) invented Spatially Offset Raman Spectroscopy (SORS). Professor Matousek is now working with a team to develop SORS, which has a wide range of applications from security scanning of liquids at airports (now deployed in 65 airports across the EU) to breast cancer and bone disease diagnosis.
Artemis is another ‘pump and probe’ laser system, but this time with short wavelength extreme ultraviolet light (XUV). The ultrashort, laser-like XUV pulses are used to capture electron dynamics in gases, liquids and at the surface of materials. Artemis combines technologies both from ultrafast lasers and synchrotrons to enable new science in the emerging field of ultrafast X-rays.
Artemis has been used to produce X-ray ‘movies’ that are helping to reveal the secrets of phenomena such as magnetism and high-temperature superconductivity, and to investigate the electronic properties of advanced materials such as graphene.
Vulcan is our most well-known laser, and will be 40 years old in 2017. Our in-house laser physics team keep Vulcan at the world leading edge of high power lasers through a continuous upgrade programme. Vulcan is currently a petawatt (1015 Watt) laser.
It delivers a focused beam – which for 1 picosecond (0.000000000001 seconds) is 10,000 times more powerful than the output of the UK National Grid – to support a wide ranging research programmes in fundamental physics, astrophysics and advanced applications relevant to novel sources of clean energy and medicine.
Gemini is our dual-beam high-power petawatt laser. It can superheat matter to millions of degrees – up to a thousand billion billion times the heat of the Sunlight on Earth. With two beams, Gemini offers combinations of long and short pulses and different focal lengths.
It allows researchers to investigate high-energy, high-density areas of physics – the kinds of conditions you’d find inside stars and planets. Experimental results from Gemini (published in Nature Communications in May 2013) were the first to demonstrate that laser light reflected from a ultrathin foil mirror moving close to the speed of light can be upshifted in energy, a demonstration of one of Albert Einstein’s special relativity concepts first published in his 1905 paper ‘On the electrodynamics of moving bodies’.
Octopus is our latest world-leading installation, a central hub of advanced tuneable lasers that are coupled to 14 microscopy work stations. Octopus gives researchers the ability to do advanced microscopy, at the right wavelength to give them the clearest view of their sample. Octopus can see down to the sub-cellular level in biological samples, and its pulses give scientists a real-time look at what’s going on in processes such as repairs to plant cells. It includes super-resolution microscopy, with a 50 nm (one thousand-millionth of a metre) resolution, and is capable of performing single molecule microscopy.
(Credit: Backstage Science)