A research team led by Hiroshi Amano, the winner of the 2014 Nobel Prize in Physics and the Institute for Sustainable Development of Materials and Systems of Nagoya University in Japan, cooperated with Asahi Kasei Co., Ltd. and successfully launched the world's first room temperature continuous wave laser emission of deep ultraviolet laser diodes (with wavelengths as low as UV-C).
The research results were published in the recent issue of Applied Physics Letters, representing a step forward in the widespread application of this technology.
Since 2017, the research team of Amano Hong has cooperated with Asahi Huacheng, which provides a 2-inch aluminum nitride substrate, to develop deep ultraviolet laser diodes. At first, it was too difficult to inject enough current into the device, which hindered the further development of ultraviolet visible (UV-C) laser diodes.
In 2019, the research team of Hiroshi Amano solved the above problems by using polarization induced doping technology, and for the first time produced a short wavelength UV-C semiconductor laser, which can work under short pulse current. The input power required for these current pulses is 5.2W, which is too high for CW laser, because the power will cause the diode to rise rapidly and stop the laser.
The researchers reshaped the structure of the device, reducing the driving power required for the laser to only 1.1W at room temperature. The researchers found that a strong crystal strain would block the effective current path. By skillfully clipping the side wall of the laser stripe, they overcome the defects, achieve high efficiency current flowing to the active area of the laser diode, and reduce the working power.
This research is a milestone in the practical application and development of semiconductor lasers in all wavelength ranges. In the future, UV-C laser diodes can be used in medical care, virus detection, particle measurement, gas analysis and high-definition laser processing, especially for surgeons and nurses who need to disinfect operating rooms and tap water.
Related links:https://phys.org/news/2022-11-scientists-world-continuous-wave-lasing-deep-ultraviolet.html
Source: Guangxingtianxia
