Recently, the national key research and development project team led by Prof. Ruan Shuangchen of Shenzhen University of Technology (SZUT), under the support of the project of "Crystal Thin-Film Processing and Preparation of New Generation of Gain Devices" of the National Key Research and Development Program of the Ministry of Science and Technology (MOST), has made important progress in research on the key scientific issues of crystal thin-film processing and preparation of new generation of gain devices. We are the first one in China to realize the crystal packaging of Yb:YAG wafer with diameter >20mm, and design the 48-stroke pumping system of kilowatt class.
High-power ultrafast lasers are used in advanced manufacturing, information, microelectronics, medical, energy, military and other fields, and the related scientific and technological application research is crucial for the promotion of national strategic development. Laser gain device is the core basic material of high power ultrafast laser, which has been highly concerned by all countries in the world. Thin-film lasers with excellent beam quality and high efficiency of optical-to-optical conversion efficiency have been widely used in many fields such as industrial manufacturing and basic scientific research. However, the lack of key core technologies such as precision processing of thin-film crystals, design and packaging of heat sink systems, and preparation of gain devices has seriously limited the further development of high-power thin-film lasers in China.
Relying on the Key Laboratory of Advanced Optical Precision Manufacturing Technology for Guangdong Universities, Shenzhen Key Laboratory of Laser Engineering, Sino-German Institute of Intelligent Manufacturing, and College of Engineering Physics, Shenzhen University of Technology has been carrying out the research on thin-flake laser technology since 2021, and adopted the self-developed thin-flake crystals with a diameter of 12 mm and regenerative amplification technology at the beginning of 2022 to realize the high power regenerative amplification of the resonance cavity through the chromatic dispersion compensation and the nonlinear effect control, the laser output with single pulse energy >500μJ, pulse width <7.5ps, and average power >200W is realized, especially the excellent performance of beam quality M2 <1.1 and optical-to-optical conversion efficiency >50%, which lays a solid foundation for the highly efficient nonlinear frequency conversion outside the cavity.
The project team adopted wavelength-locked 969nm "zero-phonon line" pumping to achieve the highest continuous output power >1300W, with a maximum optical-to-optical conversion efficiency of nearly 80%, whose excellent performance lays an important foundation for the research of kilowatt-class average power and ultrafast thin-film lasers of 100 mJ.
▲ (Left) 1000W@969nm pump (Right) 2000W@969nm pump
Through the Ministry of Science and Technology's key R & D projects, the project team is oriented to the national industrial security and major engineering construction needs, breakthroughs in high-power laser materials and devices application of key core technologies, through the innovation chain, breakthroughs in strategic high-power laser crystal preparation and application of common key technologies in all aspects, to improve China's information, energy, transportation, high-end equipment and other areas of the core laser crystal materials and devices of the independent control capabilities. It will improve the capability of independent control of core laser crystal materials and devices in the fields of information, energy, transportation and high-end equipment in China, and serve the development of new energy, 3C electronics, high-end manufacturing and other high-tech industries.
