In the range of atmospheric remote sensing, spectroscopic analysis, medical diagnosis, optical communication and direct infrared confrontation, the mid-infrared band laser is also used in the field of atmospheric window and molecular fingerprint. In the realization of infrared laser output in a variety of ways, (Ti2 / II) is a kind of rare earth ion (Tm3 + and Ho3 +) doped yttrium / lutetium aluminum garnet and transition metal ion doped II-VI compound (TM2 +: II-VI) gain material solid lasers play an important role. Recently, the Chinese Academy of Sciences Shanghai Silicic acid Salt Research Institute researcher Li Jiang led a team of transparent and optical functional ceramics, prepared a new high-quality 4at% Tm: LuAG ceramic transparent, and with the German Max Bourne Institute of Nonlinear Optics, the first time in the international implementation of the Tm: LuAG ceramic 2022nm continuous laser output 0.83W (pump source: 787nm titanium sapphire laser), the slope efficiency of up to 61% (output coupling mirror transmittance TOC = 5%), tunable laser wavelength range of 1808 ~ 2073nm. University of Engineering, the research team developed 0.8at% Ho: LuAG Ceramics achieved 2100.7nm continuous laser output 2.67W (pump source: 1907.5nm Tm: YLF laser) with a slope efficiency of 26.5% Reported the highest value), the beam quality of M2 = 1.1.
Rare earth ions (Tm3 + and Ho3 +) doped yttrium / lutetium aluminum garnet transparent ceramics have good physical and chemical properties and spectral characteristics, is a comprehensive performance of 2μm solid laser gain media.The research team prepared high-quality Tm: YAG and Ho: YAG transparent ceramic, and with the German Max Bun Institute of Nonlinear Optics to achieve a high-performance continuous laser output. Using continuous titanium sapphire laser pump source, Tm: YAG ceramic to achieve 2μm band SESAM mode-locked laser output, pulse width of 3ps , The average output power at repetition frequency of 89MHz is about 150mW.Using 1.9μm Tm fiber laser with pumped Ho: YAG ceramics to achieve 2090.4nm and 2094.0nm continuous laser output, the slope efficiency of up to 88% and 83% .Using semiconductor (SESAM), which achieves the stable mode-locking operation of Ho: YAG ceramics in the range of 2059nm to 2121nm.The research team in the new Tm / Ho: LuAG laser ceramic breakthrough, further widens the high performance middle infrared laser material The choice of category.
The use of transition metal ions doped II-VI compound polycrystalline ceramics as a gain medium solid-state lasers with ultra-wideband tuning, high quantum efficiency and other advantages, as well as the realization of high power, high energy infrared laser output potential.At the same time, due to Cr2 + / Fe2 +: II-VI, and its theoretical quality factor (FOM) is infinite, and it can also be used as a saturable absorber for medium-infrared passive Q-switched lasers.The research team uses the thermal diffusion method to prepare high Optical quality Cr: ZnS / ZnSe transparent ceramic material, and with the Harbin Institute of Technology Professor Yao Baoquan team, Cr: ZnSe ceramic gain medium to achieve the maximum power at room temperature 418mW, slope efficiency of 12.8% continuous laser output. Cr: ZnS As a saturable absorber with passive Q, a narrow pulse width, high power PQS laser output of Ho: YAP, Ho: LuAG and other lasers is realized.
Compared with the deposition thermal diffusion method, the ceramic preparation method can prevent the eutectic of the dopant in the TM: ZnS / ZnSe and the substrate at high temperature, realize the uniform distribution of the dopant ions, and make it easier to realize the structural design for better thermal management. , The ceramic has more excellent mechanical properties and thermal shock resistance, the preparation process is simple, low cost, can be scale production, etc. The research team uses wet chemical synthesis of Fe2 +: ZnS nano-powder, and then use hot-pressing sintering combined heat The high-optical quality Fe2 +: ZnS transparent ceramics was prepared by hydrostatic sintering process. The transmittance of the samples was ~ 45% at 2.0μm and the transmittance of ~ 70% at 5.0μm, which is the reported optical quality Optimum hot - pressed Fe2 +: ZnS transparent ceramics.
Research work by the National Natural Science Foundation of the project, the Chinese Academy of Sciences Frontier scientific research projects such as funding projects.
