High parametric efficiency in laser cavity-soliton microcombs

Area of Science:

• Photonics and Optical Engineering
• Nonlinear Optics
• Integrated Photonics

Background:

• Laser cavity-soliton microcombs are advanced optical pulsed sources.
• Typically implemented using microresonator-filtered fiber lasers.
• Nonlinear microcavities convert narrowband pulses into broadband microcombs.

Purpose of the Study:

• To theoretically and experimentally investigate soliton conversion efficiency.
• Focus on the 'Drop' and 'Through' ports of a four-port integrated microcavity.
• Quantify conversion efficiency for broadband microcomb generation.

Main Methods:

• Utilized a nonlinear microcavity integrated on-chip.
• Employed a four-port micro-ring resonator with a 48.9 GHz free-spectral range.
• Simultaneously measured single-soliton conversion efficiencies at different ports.

Main Results:

• Achieved 45% conversion efficiency at the 'Drop' port.
• Measured 25% conversion efficiency at the 'Through' port.
• Obtained a total on-chip conversion efficiency of 72%.

Conclusions:

• Demonstrated high soliton conversion efficiency in integrated microcavities.
• The four-port design enables efficient broadband microcomb generation.
• This work advances integrated photonic sources for optical applications.