Visible-to-mid-IR tunable frequency comb in nanophotonics

Area of Science:

• Photonics
• Nanotechnology
• Quantum Optics

Background:

• Optical frequency combs are crucial for metrology, ranging, and communications.
• Current advancements primarily focus on near-infrared combs, limiting applications requiring visible and mid-infrared spectra, especially in nanophotonics.

Purpose of the Study:

• To demonstrate widely tunable optical frequency comb generation in the visible and mid-infrared spectral regions using nanophotonic devices.
• To overcome the spectral sparsity and limitations of existing nanophotonic comb sources.

Main Methods:

• Utilized optical parametric oscillators integrated into lithium niobate nanophotonics.
• Achieved octave-spanning tunability from 1.5 to 3.3 μm with femtojoule thresholds.
• Employed up-conversion of infrared combs to generate visible combs down to 620 nm on the same chip.

Main Results:

• Demonstrated sub-picosecond optical frequency combs with ultra-broadband tunability.
• Achieved comb generation across visible (620 nm) to mid-infrared (3.3 μm) spectral ranges.
• Showcased femtojoule-level energy thresholds for comb generation on a single nanophotonic chip.

Conclusions:

• Presented a practical and universal approach for efficient nanophotonic frequency comb sources.
• Overcame spectral sparsity limitations in nanophotonic comb generation.
• Enabled versatile visible-to-mid-infrared spectral coverage for advanced applications.