Singly resonant continuous-wave optical parametric oscillator pumped by a diode laser.

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Optics

Background:

• Optical parametric oscillators (OPOs) are crucial for generating tunable laser light.
• Direct diode-laser pumping offers a compact and efficient alternative to traditional pumping methods.

Purpose of the Study:

• To demonstrate the first singly resonant continuous-wave (cw) optical parametric oscillator (SRO) directly pumped by a diode laser.
• To characterize the performance and tuning capabilities of this novel SRO.

Main Methods:

• Utilized a 38-mm-long periodically poled lithium niobate (PPLN) crystal within a four-mirror, signal-resonant ring cavity.
• Employed a 925-nm diode laser as the pump source, delivering 2.5 W of power.
• Tuned the diode laser wavelength between 924.0 and 925.4 nm to achieve wavelength tuning.

Main Results:

• Achieved generation of 480 mW of single-frequency idler radiation at 2.1 µm.
• Demonstrated tuning of the signal and idler wavelengths to 1.55–1.70 µm and 2.03–2.29 µm, respectively.
• Confirmed successful direct diode-laser pumping of a cw SRO.

Conclusions:

• The developed diode-laser-pumped SRO represents a significant advancement in compact and tunable coherent light sources.
• This technology holds promise for applications requiring specific wavelengths in the infrared spectrum.