Highly efficient 1063-nm continuous-wave laser emission in Nd:GdVO4

Area of Science:

• Lasers and Photonics
• Materials Science
• Solid-State Physics

Background:

• Neodymium-doped gadolinium vanadate (Nd:GdVO4) is a promising material for solid-state lasers.
• Achieving high efficiency in continuous-wave (CW) laser emission is crucial for various applications.
• Longitudinal pumping into the laser emitting level is an effective method for high-power laser operation.

Purpose of the Study:

• To investigate the performance of Nd:GdVO4 crystals with different doping concentrations (0.5% and 1.0% Nd) for CW laser emission.
• To evaluate the efficiency of these lasers under different pumping sources (Ti:sapphire and diode lasers).
• To analyze the factors limiting laser efficiency, such as optical losses and mode overlap.

Main Methods:

• Fabrication of 3-mm-thick Nd:GdVO4 crystals with 0.5% and 1.0% Nd doping.
• Longitudinal pumping of the crystals at 879 nm using a Ti:sapphire laser and an 879-nm diode laser.
• Measurement of laser output power, slope efficiency, optical-to-optical efficiency, and laser threshold.
• Analysis of efficiency in relation to absorbed and incident pump power.

Main Results:

• High slope efficiencies of approximately 80% were achieved with Ti:sapphire pumping for both 0.5% and 1.0% Nd:GdVO4 crystals.
• Optical-to-optical efficiencies reached up to 78% and laser thresholds were as low as 31 mW.
• Under 879-nm diode laser pumping, slope and optical-to-optical efficiencies of 60% and 53% were obtained for the 0.5% Nd:GdVO4 crystal, respectively, due to mode mismatch.

Conclusions:

• Nd:GdVO4 crystals exhibit highly efficient CW laser performance, with efficiencies close to the quantum defect limit.
• Ti:sapphire pumping provides superior efficiency due to better mode overlap compared to diode laser pumping.
• Further optimization of diode laser pumping schemes can enhance the efficiency of Nd:GdVO4 lasers.