Diode-Pumped Yb:YAG Ceramic Laser

Near infrared lasers have great potential in scientific research, industrial processing, military, medical and other fields. Because of the excellent performance, good stability, compact structure and other advantages, all solid state laser has been the hot topic in laser science and technology. The birth of laser transparent ceramic, with a lot of outstanding performances, has been extensively studied for solid state lasers with high power and muti-functions in recent years. Based on the above research background, this paper studies the laser characteristics of Yb:YAG laser transparent ceramics. The work mainly includes the following aspects:1. Using a 970 nm laser diode as the pump, We experimentally studied the high efficiency continuous wave and wavelength tuning properties of a diode-pumped domestic Yb:YAG ceramic laser. The laser performances of ceramics with different doping concentrations(1 at.%, 2 at.%, 5 at.%, 10 at.%, 15 at.%, 20 at.%) and thickness(3 mm?6 mm) were compared. With the Yb:YAG ceramic was 5mm*5mm*3mm sized and 15%(atomic percent) doped, the highest output power reached 2.4 W under the absorbed pump power of 6.3 W, and the transmittance of 2.5% OC, the slope efficiency is 47%; the highest output power of 2 W was obtained from a 6 mm 10 at.% doping ceramic, pumped by an absorbed pump power of 6.6 W and the transmittance of 2.5% OC, the slope efficiency is 41%. Wavelength tuning was realized by inserting a SF6 prism in the laser cavity, and the broadest tuning range was from 1017 to 1096 nm from a 3 mm 15 at.% doping ceramic, under a pump power of 7W and with a 0.8% OC; the broadest tuning range was from 1034 to 1096 nm from a 6 mm 10 at.% doping ceramic.2. Data processing of laser induced breakdown spectroscopy(LIBS) with Lab VIEW. In this study, We used a Q-switched laser with third harmonic generation at 355 nm to focus on the surface of the sample to generate the LIBS sprectrum. Due to the detection and correction of different continuous background noise is not easy to complete. In this work we find a way to estimate and correct the continuum background emission. First, finding all minima on a spectrum, and then set an appropriate threshold. We took out inappropriate minima and did not need to determine other groups. In the end, we use one or more polynomial functions to approximate the continuous background of the minima to meet the requirements. Using the Lab VIEW programming, this program scarcely need people's intervention, and can automatically and flexibly estimate varying continuum backgrounds over a very wide spectrum range. The method is not only limited for LIBS, but also can be useful for other spectroscopic background correction.