On-chip frequency comb generation at visible wavelengths via simultaneous second- and third-order optical...

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Visible light frequency combs are crucial for advanced applications like optical clocks and frequency metrology.
• Generating visible light combs is challenging due to material dispersion and optical loss at shorter wavelengths.
• Previous efforts have only achieved very narrow bandwidth combs below 800 nm.

Purpose of the Study:

• To develop a method for generating frequency combs in the visible light spectrum.
• To overcome the limitations of dispersion and loss in visible light comb generation.
• To utilize integrated photonics for efficient frequency comb conversion.

Main Methods:

• Employing a high-Q silicon nitride ring resonator cavity.
• Utilizing second-order optical nonlinearity for frequency conversion.
• Integrating near-infrared frequency combs into the visible range.

Main Results:

• Successfully converted a near-infrared frequency comb into the visible range.
• Demonstrated simultaneous parametric frequency comb generation, second-harmonic generation, and sum-frequency generation.
• Measured 17 comb lines in the visible spectrum, extending to 765 nm.

Conclusions:

• Integrated silicon nitride microresonators can efficiently generate visible light frequency combs.
• This technology addresses key challenges in visible light comb generation, paving the way for practical applications.
• The demonstrated method offers a new pathway for visible light frequency comb synthesis.