Enhanced high-slope-efficiency and high-power LD side-pumped Er:YSGG laser.

Area of Science:

• Laser physics
• Mid-infrared optics
• Solid-state lasers

Background:

• Erbium-doped Yttrium Scandium Gallium Garnet (Er:YSGG) lasers are valuable for mid-infrared applications.
• Optimizing laser diode (LD) pumping is crucial for achieving high output power and efficiency.

Purpose of the Study:

• To design and analyze a high-slope-efficiency, high-power laser diode side-pumped Er:YSGG laser.
• To investigate the impact of crystal dimensions and LD distribution on thermal and energy characteristics.

Main Methods:

• Detailed analysis of temperature and energy distributions within the laser crystal.
• Optimization of laser diode (LD) parameters and crystal geometry for side-pumping.
• Experimental characterization of output power, efficiency, beam quality, and divergence.

Main Results:

• Achieved a maximum output power of 34.9 W for a 2.8 µm mid-infrared laser.
• Recorded a slope efficiency of 13.7% and an optical-optical efficiency of 12.7%.
• Measured beam quality factors ($M^2$) of 5.15/5.19 and far-field divergences of 9.52/9.75 mrad.

Conclusions:

• The designed laser architecture enables high performance in terms of output power and efficiency.
• The study provides insights into optimizing LD side-pumping for Er:YSGG lasers.
• The achieved parameters are promising for various mid-infrared laser applications.