Due to its important applications in defense, medical, industrial and scientific research fields, mid-infrared laser has become one of the research hotspots in the field of laser technology at home and abroad. Practical mid-infrared nonlinear optical materials are the material basis of mid-infrared lasers. The wide transmission range, the high laser damage threshold, and the large nonlinear optical effect. In general, the phonon energy of the oxide crystals is high, which limits the application of far-infrared radiation. The research of the mid-infrared nonlinear optical crystals is mainly focused on sulfur. The phosphorus crystals are representative of semiconductor crystals, but the wide bandgap of oxides determines that such materials may have high damage thresholds and may increase the output power of existing mid-infrared lasers. The research group is facing research and application of mid-infrared oxides. Based on the long-term research of yttrium silicate system, we grasped two key factors of wide bandgap and low phonon energy. Through molecular design, La3SnGa5O14 (LGSn) crystals further selected in the yttrium silicate system are comprehensive performance. Excellent mid-infrared nonlinear optical crystals; Small size samples were obtained by crystal growth, and the infrared cutoff edge of the crystal was found to be 11 μm Infrared spectral region, with a wide band gap, high damage threshold, large nonlinear coefficient, can be used to produce mid-infrared laser and other advantages of mature near-infrared laser pumping.
Prof. Yu Haohai’s research group has been devoted to the research of artificial crystals, especially lasers and nonlinear optical crystal materials and devices. Crystal growth in optical crystals such as laser crystals, nonlinear optical crystals, laser self-frequency-doubling crystals, optical switch crystals, etc. He has achieved a series of applications in device applications. He has published many papers in international journals such as Adv. Mater., ACS Nano, Laser & Photon. Rev., Appl. Phys. Lett., and received extensive attention. Some research results have been transformed and applied. In 2014, it was suggested that the yttrium silicate system crystal may have important applications in the mid-infrared region. In 2016, the mid-infrared nonlinear optical properties and practical prospects of the lanthanum gallate crystal were evaluated.
This research work has received strong support from the National Key Research and Development Program and the National Natural Science Foundation of China.