The Effects of Focusing Position and Pump Beam Spot Sizes on End-Pumped Nd:YAG Laser Performance

The focusing position and pump beam spot sizes are critical factors in determining the performance of the end-pumped Nd:YAG laser. Understanding and optimizing these parameters can help researchers and engineers enhance the laser's efficiency, leading to improved applications in various fields. To investigate this, we conducted a series of experiments by varying the focusing position and pump beam spot sizes. The focusing position was adjusted by changing the distance between the focusing lens and the Nd:YAG crystal. The optimal output power was obtained at the position 1.5 mm inside the crystal, while the pump beam spot sizes were modified using eight different focal lenses. We found that the pump beam spot size of 450 µm led to the optimal output power at cavity lengths of 110 mm, 130 mm, and 150 mm.