High average power 2 μm generation using an intracavity PPMgLN optical parametric oscillator

Area of Science:

• Nonlinear optics
• Laser physics
• Materials science

Background:

• Optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• High-power, high-repetition-rate sources in the 2 μm wavelength range are in demand for applications like spectroscopy and remote sensing.
• MgO-doped periodically poled LiNbO(3) (PPMgLN) offers excellent nonlinear optical properties for OPO devices.

Purpose of the Study:

• To develop an intracavity quasi-phase-matched optical parametric oscillator (OPO).
• To achieve high average power and high repetition rate generation of 2 μm radiation.
• To demonstrate a compact and efficient 2 μm light source.

Main Methods:

• Utilized a degenerate OPO configuration.
• Employed a 3 mm thick MgO-doped periodically poled LiNbO(3) (PPMgLN) crystal.
• Pumped the OPO with a diode side-pumped, Q-switched 1 μm Nd:YAG laser at a 10 kHz repetition rate.

Main Results:

• Generated up to 20 W of broadband 2 μm radiation.
• Achieved a compact device configuration.
• Observed a near-circularly symmetric beam profile with M(2) ~ 10 at a crystal temperature of 115 °C.

Conclusions:

• The developed intracavity quasi-phase-matched OPO is an effective method for generating high-power 2 μm radiation.
• The compact design and performance demonstrate the potential of PPMgLN crystals in laser systems.
• This 2 μm source offers a promising solution for applications requiring high-intensity, tunable laser light.