Liangbi Su
Liangbi Su, Shanghai Institute of Ceramics, Chinese Academy of Sciences
Local structure tailoring of rare-earth doped fluoride materials for optical applications
Abstract
The traditional strategy for development of novel laser crystals mainly adopts the combination of lattice crystals and active ions, therefore the availability of spectroscopic parameters is seriously limited and can not meet the requirements of the rapidly developing laser applications. Alkaline earth fluoride crystals MF2 (M=Ca, Sr, Ba) combine the characteristics of wide transmittance range, high thermal conductivity and low phonon energy, which is favorable for application as optical components. Additionally, rare earth (RE) dopants tend to form atomic scale clusters of various structure, thus could serve as platform for tailoring local coordination of rare earth laser active ions. We proposed the strategy of designing the luminescent behaviors of rare earth doped MF2 crystals by tailoring the local coordinate structure via co-doping regulating ions. The spectroscopic parameters of RE ions could be modulated within a large range, meanwhile the energy transfers between RE dopants could be well controlled. Using RE doped MF2 crystal components of high-quality as gain materials, a series of breakthroughs in laser performances were achieved: in the ~1 micron spectral region, the laser pulse duration of solid-state laser based on Nd3+ doped CaF2 crystals was suppressed to sub-100 fs range for the first time; in the ~2 micron spectral region, CW laser of a slop efficiency of over 80% was realized using Tm3+:SrF2 crystals, corresponding to a quantum efficiency close to 200%; in the ~3 micron spectral region, high efficiency CW laser was generated using Er:CaF2 crystals and the Er3+ doping concentration (0.5 at.%) was decreased by two orders of magnitude comparing to commercial mid-infrared laser crystals. The outstanding laser performances indicate that rare earth doped fluorite-type crystals are promising candidates for high-performance solid-state lasers.
Biography
Dr. Liangbi Su is a professor and currently the director of Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS). He graduated from Wuhan University of Technology with B.S and master’s degree, and then received doctor degree from Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences in 2005. He joined SICCAS in 2008 and was the director of the Artificial Crystal Research Center of SICCAS from 2016 to 2020. Dr. Liangbi Su is the director of the “laser and optical crystals” research group in SICCAS and his interests include structure tailoring and development of novel laser crystals, as well as crystal growth and characterization of fluoride crystals for laser and optical applications. He has published more than 200 scientific papers as the first or corresponding author and is the co-author of 6 books or titled chapters. He has acquired 27 granted patents and was authorized 4 standards about fluoride crystals, including one recommended national standard. He was awarded the Excellent Young Scientists Fund of NSFC in 2014 and the National Science Fund for Distinguished Young Scholars in 2019. He is the director of the National Key R&D Program of China “Key Technologies of Crystal Growth and Applications of Large Size Laser Crystal Materials” and is the PI of several key research projects, including the CAS Project for Young Scientists in Basic Research.