Tunable optical frequency comb with hundred-GHz spacings generated on a silicon waveguide

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Optical frequency combs are crucial for precise measurements and communications.
• Generating widely spaced combs (hundred-GHz range) presents significant challenges.

Purpose of the Study:

• To demonstrate a novel method for generating tunable, widely spaced optical frequency combs.
• To utilize silicon photonics for efficient comb generation.

Main Methods:

• Generating an optical pump by multiplying a 10-GHz pulse train using temporal Talbot processing.
• Employing silicon-based cross-phase modulation to create widely spaced combs.
• Flexibly controlling the comb spacing by tuning temporal dispersion.

Main Results:

• Successfully generated optical frequency combs with tunable spacing from 140 to 200 GHz.
• Achieved a maximum carrier-to-noise suppression ratio of approximately 45 dB.
• Demonstrated the effectiveness of temporal Talbot processing for repetition rate multiplication.

Conclusions:

• Silicon-based cross-phase modulation is a viable technique for producing widely spaced optical frequency combs.
• The demonstrated method offers flexible control over comb spacing.
• This work advances the development of frequency combs for diverse applications.