High-power mid-infrared frequency comb from a continuous-wave-pumped bulk optical parametric oscillator

Area of Science:

• Nonlinear Optics
• Quantum Optics
• Spectroscopy

Background:

• Optical frequency combs (OFCs) are crucial for precision measurements.
• Generating mid-infrared OFCs is challenging but highly desirable for various applications.
• Existing methods often require complex setups or active modulation.

Purpose of the Study:

• To demonstrate a novel method for generating a mid-infrared optical frequency comb (OFC).
• To achieve mid-infrared OFC generation using a continuous-wave-pumped optical parametric oscillator (OPO) without active modulation.
• To characterize the tunability and output power of the generated mid-infrared OFC.

Main Methods:

• Utilized a continuous-wave-pumped optical parametric oscillator (OPO).
• Employed cascading quadratic nonlinearities, specifically phase-mismatched second harmonic generation.
• Transferred the OFC from near-infrared to mid-infrared via difference frequency generation within the OPO cavity.

Main Results:

• Successfully generated a mid-infrared optical frequency comb (OFC).
• Achieved tunability of the OFC from 3.0 to 3.4 µm.
• Obtained an average output power of up to 3.1 W for the mid-infrared OFC.

Conclusions:

• Demonstrated a practical and efficient method for generating mid-infrared OFCs.
• The developed technique offers a new pathway for mid-infrared frequency comb generation.
• The tunable, high-power mid-infrared OFC has potential applications in spectroscopy and sensing.