Multiwatt continuous wave Nd:KGW laser with hot-band diode pumping

Area of Science:

• Laser Physics
• Solid-State Lasers
• Photonics

Background:

• Neodymium-doped potassium gadolinium tungstate (Nd:KGW) lasers are valuable for various applications.
• Conventional pumping methods for Nd:KGW lasers often suffer from significant thermal lensing due to high quantum defects.

Purpose of the Study:

• To demonstrate the first continuous wave Nd:KGW laser utilizing hot-band diode pumping at approximately 910 nm.
• To investigate the impact of reduced quantum defect on laser performance and thermal effects.

Main Methods:

• Continuous wave laser operation of Nd:KGW crystal.
• Diode pumping at a hot-band wavelength of approximately 910 nm.
• Characterization of output power, beam quality, and efficiency.

Main Results:

• Achieved 2.9 W of average output power at 1067 nm in a diffraction-limited beam.
• Reduced quantum defect by over 46% compared to traditional ~810 nm pumping.
• Observed significantly lower thermal lensing.
• Attained a slope efficiency of 43% and an optical-to-optical efficiency of 35%.

Conclusions:

• Hot-band diode pumping at ~910 nm is an effective strategy for improving Nd:KGW laser performance.
• The reduced quantum defect and lower thermal lensing enable enhanced power and efficiency scaling.
• This approach offers a promising pathway for developing next-generation high-power solid-state lasers.