Carrier envelope offset detection via simultaneous supercontinuum and second-harmonic generation in a silicon nitride...

Area of Science:

• Photonics and Optical Engineering
• Quantum Optics
• Integrated Photonics

Background:

• Frequency combs are crucial for precise frequency measurements.
• Current methods for self-referencing frequency combs can be complex and bulky.
• Chip-scale integration offers miniaturization and improved accessibility.

Purpose of the Study:

• To demonstrate a chip-scale f-2f interferometer for carrier-envelope-offset frequency (f_CEO) detection.
• To enable a simplified route towards self-referenced frequency comb sources.
• To achieve octave-spanning supercontinuum generation and second-harmonic generation on a single chip.

Main Methods:

• Utilizing a dispersion-engineered silicon nitride waveguide.
• Simultaneously generating octave-spanning coherent supercontinuum.
• Performing second-harmonic generation within the same waveguide.
• Measuring the f_CEO beatnote of a 80 MHz modelocked pump source.

Main Results:

• Successful demonstration of a chip-scale f-2f interferometer.
• Achieved octave-spanning supercontinuum and second-harmonic generation in a single waveguide.
• Measured the f_CEO beatnote with a signal-to-noise ratio of 25 dB.
• Validated the approach for low pulse energy operation.

Conclusions:

• The developed chip-scale f-2f interferometer offers a simplified method for f_CEO detection.
• This technology paves the way for compact and accessible self-referenced frequency comb sources.
• The integrated approach is suitable for applications requiring low pulse energy operation.