Nonlinear interactions in nanowaveguides

Nanowaveguides have recently had a huge impact on the field of nonlinear optics. The strong light-matter interactions that arises from the high-confinement of light in nanowaveguides on chip allows for ultra-low threshold nonlinear interactions. At Bright, we focus on the integration of highly nonlinear materials (III/V’s, 2D materials,…) conventional silicon or silicon nitride platforms to make scalable platforms for nonlinear optical interactions. In particular, we demonstrated modulation instability low-power supercontinuum generation, soliton fission, analogs of event, frequency converters and frequency comb generation. Picture: Scanning electron microscope image of a  gallium phosphide-on-insulator ring resonator.

[1] Nondegenerate Two-Photon Absorption in Silicon Wire Waveguides in Physical Review Applied [2] An octave-spanning mid-infrared frequency comb generated in a silicon nanophotonic wire waveguide in Nature

[3] Nonlinear properties of dispersion engineered InGaP photonic wire waveguides in the telecommunication wavelength range in Optics Express

[4] Dispersive wave emission and supercontinuum generation in a silicon wire waveguide pumped around the 1550 nm telecommunication wavelength in Optics Letters

[5] On-chip parametric amplification with 26.5 dB gain at telecommunication wavelengths using CMOS-compatible hydrogenated amorphous silicon waveguides in Optics Letters

Integrated quantum optics

The activity on integrated quantum optics focuses on actively multiplexing of heralded single photon sources[1], on single photon detectors detectors, on the manipulation of two-photon states[2], and the frequency conversion of single photons [3]. Currently, we rely mostly on SiN photonics ICs that we complement with other functional elements such as nonlinear materials[4] or semiconductors. Picture : The process of four-wave mixing is used to create pairs of correlated photons [5] or change their wavelength [3] (A). It benefits strongly from the filed enhancements in microcavities (B) and it can induce strong coupling between single photons inside a cavity (C)

[1] Frequency multiplexing for quasi-deterministic heralded single-photon sources in Nature communications

[2] Strong Nonlinear Coupling in a Si3N4 Ring Resonator in Physical Review Letters

[3] Ramsey interference with single photons in Physical Review Letters

[4] Integrated silicon nitride electro-optic modulators with atomic layer deposited overlays in Optics Letters

[5] Continuous wave photon pair generation in silicon-on-insulator waveguides and ring resonators in Optics Express

Microscopy and spectroscopy

For decades, optical microscopy has played an important role in the observation of cell biology. In microscopy, as for all imaging optical system, the spatial resolution is limited. Recently, several new approaches have been developed to overcome this limit, particularly in fluorescence microscopy. We investigate the use of saturation of the two-photon absorption fluorescence excitation for improving the spatial resolution. We are also investigating the use of quantum optics technologies for high and low frequency Raman spectroscopy.

Picture: Plasmonic Raman sensor with free space resonant excitation and waveguide harvesting of Raman signal.

Picture:  3D imaging of fluorescent microspheres embedded in HeLa cells by multiphoton microscopy with resolution enhancement by fluorescence saturation

[1] 3D imaging of fluorescent microspheres embedded in HeLa cells by multiphoton microscopy with resolution enhancement by fluorescence saturation in Optics Express

[2] Surface-Enhanced Raman Spectroscopy Based on Plasmonic Slot Waveguides With Free-Space Oblique Illumination in IEEE Journal of Quantum Electronics

[3] Stimulated Raman spectroscopy of analytes evanescently probed by a silicon nitride photonic integrated waveguide in Optics Letters

Pattern formation in optical resonators

Patter formation is ubiquitous in nature. Examples include the stripes on a zebras skin and the ripples in wind-blown dunes. Through the interaction between microscopic elements of the system, a macroscopic order may spontaneously emerge when a system is brought outside of equilibrium. In optics, the interaction of a focusing nonlinearity with a diffusion -like process such as diffraction of dispersion leads to the formation of stable modulated patterns. We investigate, both experimentally and theoretically the dynamics of temporal dissipative structures in nonlinear optical resonators. Picture : ULB stored as cavity solitons in a fiber resonator

[1] Frequency comb generation through the locking of domain walls in doubly resonant dispersive optical parametric oscillators in Optics Letters
[2] Modulation Instability Induced Frequency Comb Generation in a Continuously Pumped Optical Parametric Oscillator in Physical Review Letters 

[3] Nonlinear Symmetry Breaking Induced by Third-Order Dispersion in Optical Fiber Cavities in  Physical Review Letters  

[4] Temporal cavity solitons in one-dimensional Kerr media as bits in an all-optical buffer in Nature Photonics