Diode-pumped cw Nd:YAG three-level laser at 869 nm

Area of Science:

• Laser physics
• Solid-state lasers
• Nonlinear optics

Background:

• Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) lasers are widely used for various applications.
• The (4)F(3/2)-(4)I(9/2) transition in Nd:YAG is typically utilized for 946 nm emission.
• Achieving efficient laser operation at alternative wavelengths requires innovative approaches.

Purpose of the Study:

• To report the first diode-pumped Nd:YAG laser operating at 869 nm.
• To investigate the potential for intracavity second-harmonic generation at shorter wavelengths.
• To optimize laser performance for good beam quality and power stability.

Main Methods:

• Utilizing a fiber-coupled laser diode emitting at 809 nm for pumping.
• Employing a lithium niobate (LiNbO3) crystal lens to manage thermal lensing in the Nd:YAG laser rod.
• Implementing continuous-wave (cw) operation for laser emission and frequency conversion.

Main Results:

• Achieved 453 mW of continuous-wave output power at 869 nm.
• Demonstrated intracavity second-harmonic generation, yielding 118 mW of power at 435 nm using a BiB3O6 nonlinear crystal.
• Obtained stable laser output with good beam quality due to effective thermal management.

Conclusions:

• Successfully developed a diode-pumped Nd:YAG laser operating at 869 nm, expanding the utility of this laser medium.
• The results confirm the feasibility of efficient intracavity frequency doubling for generating visible light.
• This work provides a foundation for new laser sources in the visible spectrum with high stability and beam quality.