High-power, continuous-wave, single-frequency, all-periodically-poled, near-infrared source

Area of Science:

• Lasers and Photonics
• Nonlinear Optics

Background:

• Continuous-wave (cw) optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Efficiently combining OPO with second harmonic generation (SHG) in a compact system presents engineering challenges.

Purpose of the Study:

• To report a novel, high-power, single-frequency, tunable near-infrared laser source.
• To demonstrate efficient internal second harmonic generation (SHG) from a singly-resonant optical parametric oscillator (OPO).

Main Methods:

• Utilized a Yb-fiber laser to pump a cw singly-resonant OPO.
• Employed a multigrating MgO doped periodically poled lithium niobate (MgO:PPLN) crystal for OPO.
• Integrated intracavity SHG using a fan-out grating MgO-doped stoichiometric periodically poled lithium tantalate (MgO:sPPLT) crystal.

Main Results:

• Achieved a tunable near-infrared source spanning 775-807 nm.
• Generated up to 3.7 W of near-infrared power at 793 nm and 4 W of idler power at 3232 nm.
• Demonstrated high spatial beam quality (M2<1.4) and passive power stability (<3.5% rms).

Conclusions:

• The developed source offers a compact and efficient solution for high-power, tunable laser generation.
• The combined OPO-SHG approach provides versatile output in both near-infrared and idler wavelengths.
• The system's stability and beam quality are suitable for demanding spectroscopic and photonic applications.