A University of Stuttgart start-up is using laser crystals to create new ways of performing biomedical cell analyses. The founders of Twenty-One Semiconductors became enthusiastic about laser technology during their physics studies.
At five by five millimeters, the crystal is smaller than a one-cent coin, but notwithstanding its minute dimensions, it could make a big difference for example for cancer patients, because this minuscule membrane external cavity laser (MEXL) crystal is the core component of lasers, which can be used to test the efficacy of therapies. These novel semiconductor membrane lasers are being developed for biomedical applications by Twenty-One Semiconductors (21S), a start-up spin-off from the University of Stuttgart. The company's founders, Dr. Roman Bek and Norbert Witz-Haszler, both alumni of the University, are developing them for new diagnostic and therapeutic applications in diseases, such as cancer.
Lasers generate light in different color spectra, whereby in the field of biomedical cell analysis, the yellow spectral range is particularly interesting as it enables researchers to obtain much more information about the ratio of diseased to healthy cells. “Such cell analyses are performed regularly during a therapy to determine the ratio of healthy and diseased cells, which enables one to draw conclusions about the effectiveness of the therapy,” explains Bek, chief technology officer at 21S.
Novel laser crystals are improving cell analysis
“The unique feature of our MEXL crystals is that they can be used to produce compact laser systems, which emit light in the yellow spectral range,” says managing director Witz-Haszler. Many of the lasers used in biomedicine emit light in the visible range of the spectrum between 300 and 700 nanometers. We already have some highly developed semiconductor technologies for generating lasers in the red or blue range, for example, but not in the green-yellow range of the spectrum, which leaves the so-called yellow gap. “The reason for this,” Witz-Haszler explains, “"is that it is extremely difficult to manufacture efficient semiconductor lasers that emit yellow light, because of the materials involved. “However," he continues, "this part of the spectrum can be used to obtain essential information about diseased cell tissue, which is particularly useful for biomedical cell analysis. And it is precisely this information that our MEXL technology enables us to access by enabling the production of compact laser systems for the green-yellow spectral range.”
The great thing about our work is that we get to apply what ve've learned to launch technologies that make the world a better place.
Norbert Witz-Haszler
From studying physics to founding a start-up
Founders Norbert Witz-Haszler and Dr. Roman Bek studied physics at the University of Stuttgart and were already enthusiastic about semiconductor and laser technologies at that time. They took the first step towards realizing their idea of starting their own company in late 2018. “Originally," says Witz-Haszler, "we only manufactured and sold semiconductor layers.” An EXIST-Gründerstipendium (a start-up grant available to German entrepreneurs) gave them the financial support they needed as well as free access to laboratories and equipment at the University of Stuttgart's Institute of Semiconductor Optics and Functional Interfaces (IHFG).
Eventually the two physicists went on to found Twenty-One Semiconductors GmbH in May 2019. “By the end of 2019, our sales had already put us in a position to fund ourselves,” says Bek. Then, in late 2020, they received a further cash injection from the High-Tech Gründerfonds to enable them to develop the MEXL crystals into a finished product.
“The great thing about our work,” says Witz-Haszler, “is that we get to apply what we've learned to launch technologies that make the world a better place.” The young entrepreneurs sell 95 percent of their laser crystals to manufacturers in the biomedical sector and are currently working on standardizing the production process. They also want to open up other fields of application. Witz-Haszler is confident about the future: “I don't think we've realized the full potential of our technology yet. There's still a lot that could be done with it."
Editor: Jacqueline Gehrke
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