A research group led by Hiroshi Amano, the 2014 Nobel Prize winner of the Institute of Materials and Systems for Sustainability (IMaSS) at Nagoya University in central Japan, in cooperation with Asahi Kasei, The first continuous wave laser emission of deep ultraviolet laser diode (wavelength to UV-C region) at room temperature in the world has been successfully carried out. These results were published on Applied Physics Letters, representing a step towards the practical implementation of a technology with broad application potential, including sterilization and medicine.
Since its introduction in the 1960s, after decades of research and development, laser diodes (LDs) have finally been successfully commercialized. Examples of this technology include optical communication equipment using infrared LDs and blue optical discs using blue purple LDs. However, despite the long-term efforts of research groups around the world, no one can develop deep ultraviolet LDs. Now, researchers from Nagoya University and Asahi Kasei Company have modified the structure of the device itself, reducing the driving power required for the laser to work at room temperature of only 1.1W. In the early devices, laser fringes easily led to crystal defects, which could not generate an effective current path, and the laser power was high. In this study, the researchers found that these defects were caused by strong crystal strain. So by skillfully clipping the side wall of the laser stripe, they suppressed the defects, realized effective current flow to the active area of the laser diode, and reduced the working power.
This research is a milestone for the practical application and development of semiconductor lasers in all wavelength ranges. In the future, UV-C lasers can be used in medical care, virus detection, particle measurement, gas analysis and high-definition laser processing, which may be a breakthrough in the application of sterilization technology.
This research paper has been published on Applied Physics Letters.
Source: Qianyuan
