Advancing laser technologies
Researchers funded by the Engineering and Physical Sciences Research Council (EPSRC) are driving innovations in semiconductor disk laser technology, combining physics and optical engineering techniques.
From CD players in the 80s to advancing eye surgery, hundreds of new applications have been made possible by continued innovation in laser technology.
With an interest from researchers and end-users for ultra-coherent laser sources at novel wavelengths, a five-year EPSRC-funded project, led by Dr Jennifer Hastie at the University of Strathclyde, has advanced capabilities in semiconductor disk laser (SDL) technology for optical engineering techniques.
In contrast to more conventional semiconductor lasers SDLs have very high coherence and brightness, and low noise, making them ideal for ultra-precise optical engineering. They are also very well suited to practical use and commercial development, due to their compactness, cost, and wavelength flexibility.
Jennifer Hastie, a research team leader of the Institute of Photonics at the University of Strathclyde, and whose project was funded through an EPSRC Challenging Engineering Award, said:
"This type of laser is still relatively novel, but it has unique attributes compared to other types of laser. There are many advantages to being able to bring their very high brightness and coherence to almost any wavelength from the ultra-violet to the mid-infrared, addressing significant gaps in the spectrum of lasers available to researchers and end-users who are developing next-generation technologies."
Using the award funding, Jennifer built up a team of researchers and together they spent the next five years developing the spectral brightness and tunability of the lasers at novel wavelengths. By the time the project came to an end in 2016, they had achieved record semiconductor disk laser performance, including a colour conversion breakthrough with diamond lasers.
The research gained international attention, with the team sharing the findings at global conferences and in scientific journals. It also led to Jennifer being appointed to the Management Board of the UK National Quantum Technology Hub in Sensing and Timing.
The Hub, which is EPSRC-funded as part of the UK National Quantum Technologies Programme, is supporting Jennifer’s work on developing novel lasers for high performance optical clock systems. Led by Professor Kai Bongs and Director Simon Bennet from the University of Birmingham, academics from the Universities of Glasgow, Nottingham, Southampton, Sussex and Imperial College London are also partners in the Hub’s research work, in collaboration with the National Physical Laboratory, the British Geological Survey, and more than 75 industry partners.
"The Hub is developing many technologies that will have future impact in society and on infrastructure resilience in the UK, including developing high-performance optical clocks that will revolutionise the precision with which we can measure time."
With the UK’s national infrastructure being built upon the use of a single navigation system, critical services, such as the emergency services and electricity, are at risk if it fails. Research and development in quantum clocks will support the country to have an independent time source so this risk is mitigated and increases the UK’s resilience.
Before that can happen though, scientists such as Jennifer need to be able to reduce the size of the components that go into these technologies and improve performance, at the same time.
"In order for these technologies to contribute to society, we need to get them out of the research lab and deploy them in the field. We need to make them portable so we need to make the laser systems smaller, more robust, and less power-hungry."
This is an area of research that is rapidly advancing and will be hugely beneficial to industry and to society more generally.