Important research achievements have been made in the field of new deep ultraviolet laser devices

Recently, with the support of the National Natural Science Foundation of China, Shenzhen Basic Research and other projects, Assistant Professor Jin Limin, a member of Harbin Institute of Technology (Shenzhen) Micro-nano Optoelectronics team, cooperated with Professor Wang Feng and Professor Zhu Shide of City University of Hong Kong, and published a research paper in the internationally renowned journal Nature-Communications. Harbin Institute of Technology (Shenzhen) is the communication unit.

Er3+ Sensitized Intense Deep UV On-Chip Laser Devices and Their Applications in Nanoparticle Sensing

The article points out that coherent UV light has important applications in environmental and life sciences, however direct UV lasers face limitations in direct fabrication and operating costs. The research team proposed a DUV laser strategy indirectly generated through a tandem upconversion process, that is, to construct a multi-shelled nanoparticle to achieve DUV laser output at 290 nanometers under the excitation of the 1550 nanometer long-distance communication wavelength. In the mature telecommunications industry, where various optical components are readily available, the results of this research provide a viable solution for building miniaturized short-wave lasers suitable for device applications.
Regarding the above research, the article mentions that the 1260 nm (≈3.5 eV) large anti-Stokes shift causes a series combination of a series of different upconversion processes. In this experiment, the Tm3+ and Er3+ upconversion processes are confined in different shells by multi-shell nanostructures to reduce the excitation energy dissipation caused by the uncontrollable energy exchange between different upconversion processes. This paper shows that Ce3+ doping is a necessary condition for the realization of domino upconversion, because Ce3+ suppresses the high-order upconversion of Er3+ through cross-relaxation, and realizes the population inversion dominated by the 4I11/2 energy level, which can promote the The energy transfer of Er3+→Yb3+ and the subsequent Yb3+→Tm3+ upconversion process.
The team integrated this material with a high-Q (2×105) on-chip microring laser device for optical characterization, and observed for the first time Er3+-sensitized intense deep-UV upconversion laser radiation, Tm3+ promoted by this domino upconversion process Ionic five-photon upconversion radiation is sensitive to the Q-factor of the laser cavity, and sensing measurements were performed with similar-sized polystyrene beads simulating cancer cell secretions, enabling nanoparticle sensing by monitoring 290-nm laser threshold changes , the sensing size is as small as 300 nm.