Since the 1960s, the laser diode has been studied for more than 60 years, and has developed to the scope of research from infrared light to blue -purple light and other wavelengths, with a wide range of applications. The examples of this technology include light communication equipment based on infrared laser diodes and blue -purple laser diode. However, global research teams have not yet developed deep -ultraviolet (DUV) laser diode.
At present, the Nagoya University team cooperates with the rising sunrise company (Japanese chemical enterprise), showing a DUV laser diode that emit continuous wave (CW) at room temperature. The cooperative team claims that this is the world's first DUV laser diode. This work is a milestone in the actual application of semiconductor lasers in all wavelengths, which can enable UV-C laser diode in the fields of medical care, virus detection, particle measurement, gas analysis, and high-definition laser treatment.
The team was led by Professor Akihao, the Nobel Prize winner in 2014, and the Future Materials and Systems Research Institute of Nagoya University, overcome the severe design challenges and developed a laser diode that can realize this feat.
After 2007, the emergence of the production of aluminum nitride substrate technology means that the key difficulties of the DUV laser diode can be resolved. This substrate is an ideal material for the growth of aluminum nitride (algan) thin -film of ultraviolet lighting equipment. Beginning in 2017, Tianye Hao team has cooperated with the 2 -inch rising up its rising sun. Starting from aluminum nitride (ALN) base, deep ultraviolet laser diodes are developed. At the beginning, it was very difficult to pass through the device, which hindered the further development of the UV-C laser diode.
In 2019, the team used polarization to induce doping technology to solve the above problems. For the first time, they created a short-wavelength ultraviolet visibility (UV-C) laser diode, and its working principle is mainly short pulse current.
However, the input power of these current pulses is 5.2 W, and the energy is very high. Therefore, this will cause the diode to heat up and stop the light supply.
To overcome this problem, the team has redesigned the hardware structure of the device and reduced the input power of the laser to 1.1 W at room temperature. Due to the crystal defects on laser stripes, the current path is invalid, so early equipment requires higher working power. But in this study, researchers found that the strength of the crystal caused these defects.
Through the clever tailoring of the laser striped side wall, the defects are suppressed, and the current flow of the source area of the laser diode is realized, reducing the working power.
"It is pioneering in the application of sterilization technology," said Ziyi ZHANG, which was Cheng Chengcheng. Different from the current inefficient LED sterilization method, laser can disinfect in large areas in a short time and long distance.
This technology is especially suitable for operating rooms and tap water that require disinfection.
