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

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Erbium-Ytterbium co-doped Yttrium Aluminum Borate (Er:Yb:YAB) crystals are suitable for 1.55 µm laser generation.
• Optical pumping offers an efficient method for laser excitation.
• Vertical External Cavity Surface Emitting Lasers (OP-VECSELs) provide a compact and tunable pump source.

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 configuration.
• To optimize the laser output power and beam quality.

Main Methods:

• An Er:Yb:YAB microchip laser was optically pumped using a 980-nm OP-VECSEL.
• A plano-convex lens was used to couple the pump light into 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 emitted 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 beam quality factors were measured as M²x = 1.42 and M²y = 1.38.
• The achieved beam quality is superior to previously reported single-end or dual-end pumped Er:Yb:YAB microchip lasers.

Conclusions:

• The OP-VECSEL is an effective pump source for Er:Yb:YAB microchip lasers.
• This novel pumping scheme offers improved beam quality compared to traditional methods.
• This work represents a significant advancement in the development of compact and efficient 1.55 µm fiber lasers.