German partners research electrically-pumped semiconductor disk lasers…

19 Sep 2024

…and Heriot-Watt funded by Europe to develop new attosecond laser system.

Scientists from Laser Center Hannover (“LZH”) and Berlin’s Ferdinand-Braun-Institut (FBH) are jointly researching electrically pumped semiconductor disk lasers for ultra-short pulse (USP) generation. Surface-emitting semiconductor lasers are particularly suitable for developing lasers with customized wavelengths.

Until now, optically pumped systems have been used to achieve high power levels. However, these are very complex to assemble. Electrically pumped systems, on the other hand, can only be realized with small emitting areas and therefore low power in the fundamental mode. This limits their application, for example in the field of material processing.

The researchers in the “ED-VECSEL” project are aiming to achieve electrically-pumped systems emitting in the fundamental mode with ultra-short pulses of high power and simple assembly.

To achieve this, they will investigate the feasibility of a system consisting of an electrically pumped semiconductor structure with a large emission surface and a matching resonator with, if possible, only a single additional optical component (resonator output coupler) .

As part of the project, the LZH is responsible for the investigation and integration of an optimized electrically pumped semiconductor chip into an USP laser system.

The project, called Electrically pumped semiconductor disk laser for ultrashort pulse generation (“ED-VECSEL”), is funded by Germany’s Federal Ministry of Education and Research as a scientific pre-project to investigate research questions with regard to future industrial applications in photonics and quantum technology and to build a bridge between basic research and industry-led collaborative funding.

Heriot-Watt funded by Europe to develop high-speed laser

A scientist at Heriot-Watt University, Edinburgh, UK, is to receive over £2million in European funding to “fill in the blind spots” of Nobel Prize-winning technology. Dr Christian Brahms, an assistant professor and Royal Academy of Engineering Research Fellow at the School of Engineering and Physical Sciences, is to spend the next five years building a new type of light source for extremely fast laser pulses.

His group’s aim is to capture nature’s fastest processes as they happen, at the rate of an attosecond. They say that this could allow us to see some of the fastest processes in nature, such as how plants absorb sunlight.

The Heriot-Watt project will build on the work of Pierre Agostini, Ferenc Krausz and Anne L'Huillier, who won the Nobel Prize for Physics in 2023, and address a key shortcoming of their attosecond technology: it can’t see everything.

Dr Brahms added, “Many of the most important breakthroughs in the history of science have been enabled by observing nature at scales far beyond the limits of human perception. That is exactly what we’ll be working on – pushing far beyond the limits of conventional laser sources to bring fundamental science into focus.”

The group will be working to create a new kind of laser light that mimics natural sunlight but in extremely short flashes. He said, “Current technology, like that reported by the 2023 Nobel Prize winners, can create extremely short pulses of light at ultraviolet or X-ray wavelengths.

“This incredible advance allows us to take freeze-frame images of some of the fastest microscopic processes in molecules and materials. But it is limited. In nature, these processes involve sunlight, not the wavelengths used in laboratory experiments. My aim is to create laser pulses with similar extremely short duration to conventional attosecond science sources, but at the same ultraviolet and visible wavelengths as we get from the sun. This will fill in attosecond technology’s blind spots and directly relate our knowledge of ultrafast processes to other areas, like photochemistry or materials science.”

The project will create five new jobs at Heriot-Watt: Dr Brahms will be recruiting three PhD students and two postdoctoral research associates to help design and build the laser light source. It is one of 50 in the UK to receive the European Research Council’s Starting Grant during 2024. The funding supports cutting-edge research in a wide range of fields, helping researchers to pursue the most promising ideas.

Dr. Brahms believes the funding is a vote of confidence in the UK’s technology and research culture. He said, “The ERC grants had an application success rate of just 14%. So we are officially among the most dynamic and exciting research projects in Europe.”

Professor Maria Leptin, President of the European Research Council, said: “Empowering researchers early on in their careers is at the heart of the mission of the ERC. I am particularly pleased to welcome UK researchers back to the ERC. They have been sorely missed over the past years. With fifty grants awarded to researchers based in the UK, this influx is good for the research community overall.”