Study and Experiment of Parameters Related to Small Beam Diameter of High Power Nd:YAG Laser

AbstractThis paper presents the study and experiment of parameters related to small beam diameter of high power Nd:YAG laser that greater than 50W in continuous wave mode (CW) at wavelength 1064nm. In this paper, two mirror conditions of optical cavity such as R1:750mm, R2:1000000mm and R1:508mm, R2:1000000mm are used to compare the laser performances of each Nd:YAG laser system. Here, using mirrors curvature radius of R1: 750mm, R2: 1000000mm obtains a smallest beam diameter at aperture diameter 1mm, the maximum output power of 56.88W at optical cavity length 260mm and the small beam diameter is maintained about 1mm at optical cavity length 260 − 450mm. Furthermore, compared with using mirrors curvature radius of R1: 508mm, R2: 1000000mm, the optimum current to achieve the maximum output power is lower, the optimized temperature to achieve the diode-pumped wavelength 805.5nm is higher, the beam propagation has smaller beam diameter of 1.71mm, and it has better circularity of 91%. And the beam quality is also better. Therefore, it can be concluded that R1:750mm, R2:1000000mm is the appropriate mirror condition to achieve the small beam diameter of high power Nd:YAG laser for this research