Publications de Ozan Yakar | EPFL Graph Search

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

Dissipative Kerr soliton generation at 2μm in a silicon nitride microresonator

Camille Sophie Brès, Anton Stroganov, Ozan Yakar, Marco Clementi, Christian André Clément Lafforgue, Anamika Nair Karunakaran

Chip -scale optical frequency combs enable the generation of highly -coherent pulsed light at gigahertz-level repetition rates, with potential technological impact ranging from telecommunications to sensing and spectroscopy. In combination with techniques ...

Optica Publishing Group2024

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

Photoinduced Second-Order Nonlinearities in Centrosymmetric Media

Ozan Yakar

The interaction of light and matter enables nonlinear frequency conversion and the creation of coherent currents. The optical control of electric currents is of fundamental relevance and prominent research focus in the last decades. These photocurrents ena ...

EPFL2024

Integrated Backward Second-Harmonic Generation through Optically Induced Quasi-Phase-Matching

Camille Sophie Brès, Jianqi Hu, Edgars Nitiss, Ozan Yakar

Quasi-phase-matching for efficient backward second-harmonic generation requires sub-μm poling periods, a nontrivial fabrication feat. For the first time, we report integrated first-order quasiphase-matched backward second-harmonic generation enabled by see ...

2023

Mid-IR Soliton Microcomb Generation in Silicon Nitride Microring Resonators

Camille Sophie Brès, Ozan Yakar, Marco Clementi, Christian André Clément Lafforgue

We demonstrate soliton Kerr-comb generation in a high-Q silicon nitride microring with 143 GHz free spectral range pumped at 1970 nm. The resulting low noise ultrafast pulse train displays a 422 nm bandwidth, extending up to 2250 nm. ...

2023

Photo-induced cascaded harmonic and comb generation in silicon nitride microresonators

Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Jianqi Hu, Wenle Weng, Jijun He, Edgars Nitiss, Ozan Yakar

Silicon nitride (Si3N4) is an ever-maturing integrated platform for nonlinear optics but mostly considered for third-order [chi(3)] nonlinear interactions. Recently, second-order [chi(2)] nonlinearity was introduced into Si3N4 via the photogalvanic effect, ...

2022

Generalized Coherent Photogalvanic Effect in Coherently Seeded Waveguides

Camille Sophie Brès, Jianqi Hu, Edgars Nitiss, Ozan Yakar

The coherent photogalvanic effect leads to the generation of a current under the absorption interference of coherent beams and allows for the inscription of space-charge gratings leading to a second-order susceptibility (chi((2))). The inscribed grating au ...

2022

Backward Second-Harmonic Generation in Optically Poled Silicon Nitride Waveguides

Camille Sophie Brès, Jianqi Hu, Edgars Nitiss, Ozan Yakar

We report the inscription of quasi-phase-matching gratings in silicon nitride waveguides for backward second-harmonic-generation enabled by all-optical poling, therefore, circumventing the difficulties in inscribing poled domains with ultra-short periods. ...

2022

Difference-frequency generation in optically poled silicon nitride waveguides

Rui Ning Wang, Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Edgars Nitiss, Ozan Yakar, Boris Zabelich, Ezgi Sahin

Difference-frequency generation (DFG) is elemental for nonlinear parametric processes such as optical parametric oscillation and is instrumental for generating coherent light at long wavelengths, especially in the middle infrared. Second-order nonlinear fr ...

WALTER DE GRUYTER GMBH2021

Difference-frequency generation in silicon nitride waveguides based on all-optical poling

Camille Sophie Brès, Edgars Nitiss, Ozan Yakar, Boris Zabelich, Ezgi Sahin

IEEE2021

Seeded Multimode Quasi-Phase-Matching in All-Optically Poled Silicon Nitride Waveguides

Camille Sophie Brès, Edgars Nitiss, Ozan Yakar

We demonstrate seeding-enabled all-optical poling of silicon nitride waveguides as short as 5 mm, and account for quasi-phase-matching (QPM) inside the waveguide between the fundamental mode of pump and higher order second-harmonic modes. ...

OSA2021

Difference frequency generation in optically poled silicon nitride waveguides

Camille Sophie Brès, Edgars Nitiss, Ozan Yakar, Boris Zabelich, Ezgi Sahin

All-optical poling leads to an effective second-order nonlinearity (chi((2))) in centrosymmetric materials without the need for sophisticated fabrication techniques or material processing, through the periodic self-organization of the charges. The absence ...

SPIE-INT SOC OPTICAL ENGINEERING2021

Broadband quasi-phase-matching in dispersion-engineered all-optically poled silicon nitride waveguides

Rui Ning Wang, Tobias Kippenberg, Camille Sophie Brès, Junqiu Liu, Edgars Nitiss, Ozan Yakar, Boris Zabelich

Quasi-phase-matching (QPM) has become one of the most common approaches for increasing the efficiency of nonlinear three-wave mixing processes in integrated photonic circuits. Here, we provide a study of dispersion engineering of QPM second-harmonic (SH) g ...

2020

Highly tunable second-harmonic generation in all-optically poled silicon nitride waveguides

Camille Sophie Brès, Anton Stroganov, Edgars Nitiss, Ozan Yakar

The availability of nonlinear parametric processes, such as frequency conversion in photonic integrated circuits is essential. In this contribution, we demonstrate a highly tunable second-harmonic generation in a fully complementary metal–oxide–semiconduct ...

2020