Compact OP-VECSEL-pumped Er:Yb:YAB microchip laser with M² < 1.5 at 1.55 µm

Area of Science:

• Laser Physics
• Materials Science
• Optoelectronics

Background:

• Erbium-Ytterbium co-doped Yttrium Aluminum Borate (Er:Yb:YAB) crystals are suitable for 1.55 µm laser applications.
• Optical pumping is a common method for exciting laser gain media.
• Vertical External Cavity Surface Emitting Lasers (OP-VECSELs) offer tunable and high-power pumping capabilities.

Purpose of the Study:

• To report the first demonstration of an Er:Yb:YAB laser pumped by an OP-VECSEL.
• To investigate the performance characteristics of this novel laser system.
• To compare the beam quality with previously reported Er:Yb:YAB microchip lasers.

Main Methods:

• An Er:Yb:YAB microchip laser was optically pumped using a 980-nm OP-VECSEL.
• A plano-convex lens was used to focus the pump beam onto the laser crystal.
• The OP-VECSEL's output wavelength was tuned to the crystal's absorption peak by adjusting the cooling temperature.
• Laser output power and beam quality were measured.

Main Results:

• The Er:Yb:YAB laser successfully operated at 1.55 µm when pumped by the OP-VECSEL.
• A maximum output power of 0.232 W was achieved with 2.32 W of pump power.
• The laser beam quality factors were M²x = 1.42 and M²y = 1.38, indicating good beam quality.
• The laser cavity length was kept under 100 mm.

Conclusions:

• This study presents the first successful implementation of an OP-VECSEL-pumped Er:Yb:YAB laser.
• The developed laser system demonstrates efficient power conversion and superior beam quality compared to other pumping methods.
• This work opens new avenues for compact and high-performance 1.55 µm fiber laser sources.