Yuya Koshiba, a recipient of the prestigious MERIT fellowship awarded in the program’s first call, has been pursuing a 30-month research project at the HiLASE Center, a top-tier facility in Dolní Břežany developing new lasers. His project aims to develop a powerful and very fast laser that operates at a specific wavelength of light. The research could lead to new applications in technologies used in space. His research stay in the Central Bohemian Region is funded by the MERIT program of the Central Bohemian Innovation Center.
How did you find your way to the HiLASE Center in Dolní Břežany?
During my PhD studies in Japan, I had the opportunity to complete an internship here in 2017 and learn more about the lasers being developed here. After completing my PhD, I wanted to continue with postdoctoral research abroad. HiLASE is a top-notch facility, so I inquired if they had a position for me.
I came here in 2022, and my supervisor told me about the MERIT program of the Central Bohemian Innovation Center (SIC), which involves foreign researchers in research in the Central Bohemian Region and supports them. I applied and subsequently received funding. SIC offers financial support for 30 months.
What are the advantages of MERIT program funding for your research compared to other types of funding, such as those your colleagues might have?
It’s great that the funds from the Mobility Programme for Excellence in Research, Innovation and Technology (MERIT) are flexible, so they cover both my salary and conference trips, as well as some laboratory equipment and supplies. This is what makes this type of funding great – I have trust and can handle the funds relatively freely. It’s different from other, often very rigid grants that my colleagues have. I even earn a higher salary than in Japan.
Do you plan to stay here after the MERIT program ends?
Yes, I am very happy here and would like to continue my research, as my project is far from over.
Thin-Disk Lasers Not Only for Space Applications What are you working on at HiLASE?
One of the main research directions is the development of lasers, and I am part of the ALD Laboratory (Advanced Laser Development Department), where we develop so-called thin-disk lasers, in which the laser light is generated through thin disks. Lasers always have an active medium. Traditionally, the active medium was in the form of thin rods, similar to those in laser pointers. When you need to generate a stronger and more powerful laser, rods no longer suffice, as such a laser generates a lot of heat. Thin disks are easier to cool. In space, where there is no atmosphere, cooling presents a significant challenge, and technical devices can only dissipate heat by radiating energy.
The disk acts as an amplifier for the laser beam, and the laser apparatus also includes various mirrors that direct the beam. The goal is to create a new type of laser amplifier using a material called Ho, which can emit light around 2090 nm.
What is this material?
Ho stands for Holmium. It’s an element from the lanthanide group, a white transition metal. The Holmium ion is part of the YAG crystal, which then acts as the laser itself. In Turnov, there’s a company called CRYTUR that manufactures these crystals, so we collaborate with them.
Your project aims to develop a powerful laser operating at a specific wavelength of 2 µm. What is the typical wavelength of lasers, and why is it necessary to develop this one?
The most common lasers have a wavelength of around one micrometer. For example, if we talk about a laser pointer, if it’s red, its wavelength is 634 nanometers, which is still visible light. The lasers we work with are no longer visible.
Why develop a laser with a 2 µm wavelength? Lasers with a wavelength of one micrometer have reached their maximum and can no longer be improved. Therefore, we shifted to a different wavelength. In addition, there are emerging applications for which lasers with a 1 µm wavelength are no longer sufficient.
How do you visualize lasers that are invisible due to their wavelength?
We aim them at a wall or paper, and we have special cameras that can “see” these wavelengths.
What applications will your laser be suitable for?
Our powerful 2 µm laser could serve as a sensor for atmospheric gases. One of the research areas we focus on at HiLASE is space applications, so these lasers could be mounted on satellites in the future and used to examine the composition of gases, for example, on Mars.
Likewise, these lasers can be used for communication between individual satellites and Earth. A two-micron laser has a more stable beam in the atmosphere than those currently used in space, which could make space communication easier.
Will the disk amplifier be used not only in space but also on Earth?
Our amplifier will be used for high-energy laser pulses in the laboratory. One application is called LIDT (Laser Induced Damage Threshold). Since this laser will be highly efficient and powerful, it can be used to test the quality and durability of various materials used in challenging environments or even in space. Another possible application is in healthcare for certain types of examinations.
How big is the team working on the laser?
My team consists of four people. This is the group working on the mentioned thin-disk amplifier. However, more laboratories and partners from companies and universities are involved in the entire project. Everyone focuses on their part of the final laser apparatus.
How far along are you in developing the laser?
We are still at the beginning, in the basic research phase. I must first demonstrate that it works as we envision and as we designed the amplifier and apparatus. We need to confirm that we can produce such a strong laser light signal.
Better than in Japan You are from Japan; how do you like living in the Czech Republic, in Dolní Břežany?
Given that our center is truly multicultural and I live in Prague, I have no problems with language or fitting in. I am very satisfied here; everyone is very nice and friendly.
How is work generally at HiLASE? What level is the research here compared to Japan?
High. For example, we have a so-called clean room, where we go in special suits and where the air is purified, which is necessary for precise work with sensitive laser apparatus. Only in this way can we work at the highest level. In Japan, we didn’t have this clean room. In general, the laboratory equipment is new and modern. Moreover, we have another top facility, ELI Beamlines, nearby, so we can share ideas and some equipment. It’s a very good environment for high-level research, and I’m glad that SIC is aware of this and allows foreign researchers to work here.
Do you already have any future plans?
They are difficult to make right now, as there’s still a lot of work on the current project, which will require a lot of optimization. It would be great if my laser could eventually see final application. However, that’s still a long way off.
