Surpassing the nonlinear conversion efficiency of soliton microcombs.

Area of Science:

• Photonics
• Quantum Optics
• Integrated Photonics

Background:

• Laser frequency combs are crucial for applications like optical clocks and exoplanet detection.
• Dissipative Kerr solitons in microresonators offer miniaturized frequency comb solutions.
• Current methods for soliton microcombs suffer from low power conversion efficiency (~1%).

Purpose of the Study:

• To overcome the fundamental limitation of low power conversion efficiency in soliton microcombs.
• To demonstrate a novel technique for enhancing the performance of integrated photonic frequency combs.

Main Methods:

• Inducing a controllable frequency shift to a selected cavity resonance.
• Utilizing two linearly coupled anomalous-dispersion microresonators.
• Experimentally realizing coherent dissipative Kerr soliton generation.

Main Results:

• Achieved a power conversion efficiency exceeding 50% for dissipative Kerr solitons.
• Demonstrated excellent line spacing stability in the generated soliton microcomb.
• Observed vastly modified soliton dynamics due to the induced frequency shift.

Conclusions:

• The developed method effectively overcomes the efficiency limitations of conventional soliton microcombs.
• This approach facilitates the practical implementation of scalable, energy-efficient integrated photonic architectures.
• The results pave the way for advanced applications in sensing, metrology, and communication.