Supercontinuum generation in a nonlinear ultra-silicon-rich nitride waveguide

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Supercontinuum generation is crucial for broadband light sources.
• Ultra-silicon-rich nitride (USRN) offers unique nonlinear optical properties.
• Achieving high spectral coherence in supercontinuums is challenging but essential for applications.

Purpose of the Study:

• To demonstrate supercontinuum generation in a short USRN waveguide.
• To experimentally and numerically investigate the spectral coherence of the generated supercontinuum.
• To assess the potential of USRN waveguides for CMOS-compatible light sources.

Main Methods:

• Fabrication of a 3-mm-long USRN waveguide.
• Launching 500 fs pulses at 1555 nm with 17 pJ energy.
• Experimental characterization of spectral coherence using interferometric methods.
• Numerical simulations using the generalized nonlinear Schrödinger equation.

Main Results:

• Successfully generated broadband supercontinuum in a 3-mm USRN waveguide.
• Achieved high spectral coherence with an average |g12| > 0.90 from 1260 nm to 1700 nm.
• Experimental results showed excellent agreement with theoretical simulations.

Conclusions:

• USRN waveguides enable efficient generation of spectrally coherent supercontinuum.
• The demonstrated performance is suitable for CMOS-compatible light source development.
• This work paves the way for applications in self-referencing, metrology, and imaging.