arXiv subjects

Florent Mazeas

Publications and source records attributed to Florent Mazeas.

6 recordsLinked to original sources

arXiv2022

Near perfect two-photon interference out a down-converter on a silicon photonic chip

Integrated entangled photon-pair sources are key elements for enabling large-scale quantum photonic solutions, and addresses the challenges of both scaling-up and stability. Here we report the first demonstration of an energy-time entangled photon-pair source based on spontaneous parametric down-conversion in silicon-based platform through an optically induced second-order ($χ^{(2)}$) nonlinearity, ensuring type-0 quasi-phase-matching of fundamental harmonic and its second-harmonic inside the waveguide. The developed source shows a coincidence-to-accidental ratio of 1635 at 8 of $μ$W pump power. Remarkably, we report two-photon interference with near-perfect visibility of 99.36$\pm1.94\%$, showing high-quality photonic entanglement without excess background noise. This opens a new horizon for quantum technologies requiring the integration of a large variety of building functionalities on single chips.

quant-ph↗

arXiv2021

Quantum-limited determination of refractive index difference by means of entanglement

Shaping single-mode operation in high-power fibres requires a precise knowledge of the gain-medium optical properties. This requires accurate measurements of the refractive index differences ($Δ$n) between the core and the cladding of the fiber. We exploit a quantum optical method based on low-coherence Hong-Ou-Mandel interferometry to perform practical measurements of the refractive index difference using broadband energy-time entangled photons. The precision enhancement reached with this method is benchmarked with a classical method based on single photon interferometry. We show in classical regime an improvement by an order of magnitude of the precision compared to already reported classical methods. Strikingly, in the quantum regime, we demonstrate an extra factor of 4 on the accuracy enhancement, exhibiting a state-of-the-art $Δ$n precision of $6.10^{-7}$. This work sets the quantum photonics metrology as a powerful characterization tool that should enable a faster and reliable design of materials dedicated to light amplification.

quant-ph↗

arXiv2020

High-quality photonic entanglement based on a silicon chip

The fruitful association of quantum and integrated photonics holds the promise to produce, manipulate, and detect quantum states of light using compact and scalable systems. Integrating all the building-blocks necessary to produce high-quality photonic entanglement in the telecom wavelength range out of a single chip remains a major challenge, mainly due to the limited performance of on-chip light rejection filters. We report a stand-alone, telecom-compliant, device that integrates, on a single substrate, a nonlinear photon-pair generator and a passive pump rejection filter. Using standard channel-grid fiber demultiplexers, we demonstrate the first entanglement quantification of such a integrated circuit, showing the highest raw quantum interference visibility for energy-time entangled photons over two telecom-wavelength bands. Genuinely pure maximally entangled states can therefore be generated thanks to the high-level of noise suppression obtained with the pump filter. These results will certainly further promote the development of more advanced and scalable photonic-integrated quantum systems compliant with telecommunication standards.

quant-ph↗

arXiv2019

Fibre based hyperentanglement generation for dense wavelength division multiplexing

Entanglement is a key resource in quantum information science and associated emerging technologies. Photonic systems offer a large range of exploitable entanglement degrees of freedom such as frequency, time, polarization, and spatial modes. Hyperentangled photons exploit multiple degrees of freedom simultaneously to enhance the performance of quantum information protocols. Here, we report a fully guided-wave approach for generating polarization and energy-time hyperentangled photons at telecom wavelengths. Moreover, by demultiplexing the broadband emission spectrum of the source into five standard telecom channel pairs, we demonstrate compliance with fibre network standards and improve the effective bit rate capacity of the quantum channel up to one order of magnitude. In all channel pairs, we observe a violation of a generalised Bell inequality by more than 27 standard deviations, underlining the relevance of our approach.

quant-ph↗

arXiv2017

Optical pump-rejection filter based on silicon sub-wavelength engineered photonic structures

The high index contrast of the silicon-on-insulator (SOI) platform allows the realization of ultra-compact photonic circuits. However, this high contrast hinders the implementation of narrow-band Bragg filters. These typically require corrugations widths of a few nanometers or double-etch geometries, hampering device fabrication. Here we report, for the first time, on the realization of SOI Bragg filters based on sub-wavelength index engineering in a differential corrugation width configuration. The proposed double periodicity structure allows narrow-band rejection with a single etch step and relaxed width constraints. Based on this concept, we experimentally demonstrate a single-etch, $\mathbf{220\,nm}$ thick, Si Bragg filter featuring a corrugation width of $\mathbf{150\,nm}$, a rejection bandwidth of $\mathbf{1.1\,nm}$ and an extinction ratio exceeding $\mathbf{40\,dB}$. This represents a ten-fold width increase compared to conventional single-periodicity, single-etch counterparts with similar bandwidths.

physics.optics↗

arXiv2017

High-quality photonic entanglement for wavelength-multiplexed quantum communication based on a silicon chip

We report an efficient energy-time entangled photon-pair source based on four-wave mixing in a CMOS-compatible silicon photonics ring resonator. Thanks to suitable optimization, the source shows a large spectral brightness of 400\,pairs of entangled photons /s/MHz for $\rm 500\,μW$ pump power. Additionally, the resonator has been engineered so as to generate a frequency comb structure compatible with standard telecom dense wavelength division multiplexers. We demonstrate high-purity energy-time entanglement, i.e., free of photonic noise, with near perfect raw visibilities ($>$~98\%) between various channel pairs in the telecom C-band. Such a compact source stands as a path towards more complex quantum photonic circuits dedicated to quantum communication systems.

quant-ph↗