Publications by Ji Zhou | EPFL Graph Search

Disorder-assisted real–momentum topological photonic crystal

Romain Christophe Rémy Fleury, Haoye Qin, Bo Li, Ji Zhou

Topological defects and disorder counteract each other. Intuitively, disorder is considered detrimental, requiring efforts to mitigate its effects in conventional topological photonics. We propose a counter-intuitive approach that exploits a real–momentum ...

Springer Science and Business Media LLC2025

Ultrabroadband milliwatt-level resonant frequency doubling on a chip

Camille Sophie Brès, Marco Clementi, Ji Zhou

Microresonators are powerful tools to enhance the efficiency of second-order nonlinear optical processes, such as second-harmonic generation, which can coherently bridge octave-spaced spectral bands. However, dispersion constraints such as phase-matching a ...

Springer Science and Business Media LLC2025

Self-organized spatiotemporal quasi-phase-matching in microresonators

Camille Sophie Brès, Jianqi Hu, Anton Stroganov, Edgars Nitiss, Ozan Yakar, Marco Clementi, Ji Zhou

Quasi-phase-matching (QPM) is a widely adopted technique for mitigating stringent momentum conservation in nonlinear optical processes such as second-harmonic generation (SHG). It effectively compensates for the phase velocity mismatch between optical harm ...

Springer Science and Business Media LLC2025

Spatiotemporal Quasi-Phase-Matching in Microresonators

Camille Sophie Brès, Jianqi Hu, Edgars Nitiss, Ozan Yakar, Marco Clementi, Ji Zhou

We show how spatiotemporal quasi-phase-matching emerges from all-optical poling of silicon nitride microresonators. Enabled by the coherent photogalvanic effect, the photoinduced χ(2) grating oscillates in space and time, yielding quasi-phase-matched and D ...

Institute of Electrical and Electronics Engineers Inc.2024

Versatile and Efficient Dual-Range Frequency Shifts by Intracavity Epsilon-Near-Zero Nanolayers

Camille Sophie Brès, Jiaye Wu, Marco Clementi, Ji Zhou

We experimentally demonstrate for the first time, the efficient input-dependent dual-range frequency shifts of 279.73 GHz and 3.63 THz in a mode-locked fiber laser with an intracavity epsilon-near-zero element. Real-time observation reveals that the presen ...

Institute of Electrical and Electronics Engineers Inc.2024

Intracavity Epsilon-Near-Zero Dual-Range Frequency Switch

Camille Sophie Brès, Jiaye Wu, Marco Clementi, Ji Zhou

Epsilon-near-zero (ENZ) nanophotonic devices with zero permittivity are known to exhibit adiabatic frequency translation via temporal refraction under extracavity excitation by intense light sources, which are however hard to integrate on-chip owing to a h ...

2024

Second-Harmonic Generation via All-Optical Poling in Linearly Uncoupled Silicon Nitride Microresonators

Camille Sophie Brès, Marco Clementi, Ji Zhou

We present a novel device consisting of two microring resonators coupled by the second-order nonlinear interaction. By independently controlling the microresonators' linear properties, we engineer efficient second-harmonic generation through photo-induced ...

Institute of Electrical and Electronics Engineers Inc.2024

Broadband Resonant Second-Harmonic Generation in Silicon Nitride Microresonators

Camille Sophie Brès, Marco Clementi, Ji Zhou

We develop a device consisting of two silicon nitride microresonators coupled by photo-induced second-order nonlinearity. By electrically reconfiguring its linear properties, we engineer efficient resonant frequency doubling in the telecom band and show th ...

Institute of Electrical and Electronics Engineers Inc.2024

A universal route to efficient non-linear response via Thomson scattering in linear solids

Cheng Wang, Gabriel Aeppli, Joe Martin Bailey, Junjie Li, Min Chen, Ji Zhou

Non-linear materials are cornerstones of modern optics and electronics. Strong dependence on the intrinsic properties of particular materials, however, inhibits the at-will extension of demanding non-linear effects, especially those second-order ones, to w ...

OXFORD UNIV PRESS2023

Fabrication of alloyed plasmonic nanostructures

Olivier Martin, Debdatta Ray, Haohua Li, Ji Zhou

We have fabricated homogeneous thin films of an alloy of Au and Ag, by annealing two consecutive deposited layers of Au and Ag. We have also successfully fabricated nanodisks and nanorods made of AuAg alloys by annealing the nanostructures at 300 degrees C ...

IEEE2018