Work

Broadband spectral mapping of photo-induced second-harmonic generation in silicon nitride microresonators

Year: 2025

Type: article

Abstract: By employing a pump-probe technique for enhanced spectral mapping of the dynamics in nonlinear frequency conversion, we demonstrate that photo-induced second-harmonic generation (SHG) in silicon nitride (Si 3 N 4 ) microresonators can persist when transitioning from the preferred doubly resonant condition–where the resonances of the optical harmonics are required to be matched–to a highly detuned state where the generated second harmonic is significantly shifted away from its corresponding resonance. This results in an unconventionally broad conversion bandwidth. Other intriguing phenomena, such as detuning-dependent all-optical poling and nonlinear multi-mode interaction, are also presented, to the best of our knowledge, for the first time with direct experimental evidence. Our findings provide new insights into the physics of photo-induced second-order ( χ (2) ) nonlinearity, highlighting its potential applications for nonlinear χ (2) photonics in an integrated Si 3 N 4 platform.

Source: Optics Express

DOI: 10.1364/oe.572780

Authors: Ji Zhou, Marco Clementi, Samantha Sbarra, Ozan Yakar, Camille-Sophie Brès

Language: English

Topic: Photorefractive and Nonlinear Optics

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, HORIZON EUROPE European Research Council

Awards: G4936377417, Frequency conversion in engineered and optically controllable nonlinear Si-photonics microresonators