Pure-three-level Yb:GdCOB CW laser at 976  nm

Area of Science:

• Laser Physics
• Solid-State Lasers
• Nonlinear Optics

Background:

• Ytterbium-doped materials are crucial for developing efficient solid-state lasers.
• The F5/2-F7/2 transition in Yb3+ ions typically results in quasi-three-level emission, posing challenges for pure three-level operation.
• Gadolinium Calcium Oxyborate (GdCOB) is a promising host crystal for laser applications.

Purpose of the Study:

• To demonstrate the first pure-three-level Ytterbium-doped Gadolinium Calcium Oxyborate (Yb:GdCOB) laser operating at 976 nm.
• To investigate the potential for self-frequency-doubling in this system for blue light generation.
• To achieve high output power in continuous-wave (CW) operation.

Main Methods:

• Utilizing a Yb:GdCOB crystal as the gain medium.
• Pumping the Yb:GdCOB laser with a quasi-three-level Nd:SrLaAlO4 laser at 902 nm.
• Operating the laser in continuous-wave (CW) mode.
• Employing a nonlinear crystal for self-frequency doubling to generate blue light.

Main Results:

• Achieved a maximum CW output power of 782 mW at 976 nm from the Yb:GdCOB laser.
• Successfully demonstrated a self-frequency-doubling CW blue laser with a maximum output power of 133 mW at 488 nm.
• Confirmed pure-three-level laser operation at 976 nm, deviating from the typical quasi-three-level emission at 1032 nm.

Conclusions:

• The Yb:GdCOB crystal is suitable for pure-three-level laser operation at 976 nm.
• High-power blue laser generation is feasible through self-frequency doubling in this system.
• This work opens new avenues for compact and efficient visible laser sources.