Far-UVC compact laser module

Figure 1: Set-up of a far-UVC laser system consisting of a GaN DFB laser and SOA as MOPA and a SHG by a non-linear crystal

This project is a collabaration with two groups at the Ferdinand Braun Institut (FBH) in Berlin and our group at Chemnitz University of Technology. The first team from FBH is lead by Dr. S. Einfeldt and the second team is managed by Dr. K. Paschke.
Far UV-C emission range resembles wavelength below 235 nm and can be used for different application. An important field of application is the utilization for disinfection, as far UV-C radiation is safe for humans and leaves no damage to DNA as it is absorbed and scattered by biofilms on the skin or top dead corneal cells. To generate far UV-C light there are different options: (1) direct UV-C emitting LDs, (2) second harmonic generation (SHG) with blue-violet LDs, or (3) higher-harmonic generation with red or infrared LDs.
In this project, a far UV-C laser system will be developed. A schematic representation of the system is given in fig. 1. The laser system consists of the GaN DFB single-mode LD with monolithically integrated grating in combination of a semiconductor optical amplifier (SOA), which together forms the master oscillator power amplifier (MOPA). These devices are not available on the world market and must therefore be developed and miniaturized in the course of the project. Blue-violet GaN DFB rigde waveguide lasers with a lateral and longitudinal single mode operation developed by FBH will be used. The SHG is performed with a resonant cavity in bow-tie symmetry using a nonlinear BBO crystal. The resonant cavity is used to boost the SHG. Furthermore, a non-linear BBO is used, as standard crystals cause problems at the target wavelength. The aim of this project is to development and analyze a functioning laser system with far UV-C output emission with a wavlength of 210nm and an output power of 1 mW. The value of the output power corresponds to the radiation power required for disinfection purposes.

The development of the violet lasers and amplifier chip will be carried out by FBH. The miniaturization of the violet MOPA and compact far UVC lasers is also done at FBH. Our group focuses on understanding the performance of the laser module and the evaluation of the components and systems as well as the frequency conversion.
project start: January 2025