On-chip generation of heralded photon-number states

Abstract

Beyond the use of genuine monolithic integrated optical platforms, we report here a hybrid strategy enabling on-chip generation of configurable heralded two-photon states. More specifically, we combine two different fabrication techniques, i.e., non-linear waveguides on lithium niobate for efficient photon-pair generation and femtosecond-laser-direct-written waveguides on glass for photon manipulation. Through real-time device manipulation capabilities, a variety of path-coded heralded two-photon states can be produced, ranging from product to entangled states. Those states are engineered with high levels of purity, assessed by fidelities of 99.5 ± 8% and 95.0 ± 8%, respectively, obtained via quantum interferometric measurements. Our strategy therefore stands as a milestone for further exploiting entanglement-based protocols, relying on engineered quantum states, and enabled by scalable and compatible photonic circuits.

Integrated sources of entangled photons at the telecom wavelength in femtosecond-laser-written circuits

“…Here, we report on the fabrication and characterization of a fully integrated optical source for pathand polarization-entangled photon-pairs. Exploiting femtosecond-laser-written photonic circuits, we demonstrate the flexibility of the interferometric approach [29][30][31] to generate different quantum states of light and the feasibility of a hybrid-material assembly to develop highperformance and re-arrangeable microsystems for quantum information science.…”

Frequency-Multiplexed Photon Pairs Over 1000 Modes from a Quadratic Nonlinear Optical Waveguide Resonator with a Singly Resonant Configuration

“…[16], the experiment focused on the narrow-band single photon generation as in the case of the photon pair generation by the doubly-resonant OPO [17][18][19][20][21][22][23][24][25].In this paper, we demonstrate a frequency multiplexed photon pair generation based on a quadratic nonlinear optical medium with the SR OPO configuration. In the experiment, we used a periodically-poled lithium niobate (PPLN) waveguide as the nonlinear optical medium which is widely used in the quantum information experiments [26,27] and has a possibility to integrate into an on-chip photonic circuit [27][28][29][30][31]. In our experiment, a pair of photons is generated into a long and a short wavelength comb-like mode.…”

On-chip III-V monolithic integration of heralded single photon sources and beamsplitters

“…exploiting parametric down-conversion in PPKTP [12] or PPLN [13,14] waveguides, or four-wave mixing in silicon [15,16] and silica [17,18] waveguides, to produce single-photon states of high purity and indistinguishability, at room temperature and telecom wavelength. Several parametric sources can be integrated on a single chip, paving the way to large scale operations [18][19][20][21].An important challenge now is to combine the progress on sophisticated linear circuits and high-performance single-photon sources to achieve generation and manipulation on a single chip. First experimental results in this direction are promising, either with hybrid technology -e.g.…”

“…First experimental results in this direction are promising, either with hybrid technology -e.g. PPLN sources with laser-written glass circuits [19,21] or III-V quantum dots with silica circuits [22]or with monolithic technology on PPLN [23][24][25][26], Silicium [18,20] or GaAs [27][28][29][30][31][32].In particular, the recent integration of III-V quantum dots and beamsplitters on GaAs points to a notably flexible platform [27][28][29][30][31][32]. Indeed, GaAs offers several assets for integrated quantum photonics [33,34]: it can host both two-level [10,35] and parametric emitters [36][37][38], its direct band gap enables electrically injected sources [35,39], its high electro-optic effect allows for fast phase shifters [40], and it can be combined with superconducting nanowires to achieve on-chip detection [41].Here, we report the first realization of a monolithic GaAs/AlGaAs photonic circuit combining a parametric heralded single-photon source with a beamsplitter.…”

“…First experimental results in this direction are promising, either with hybrid technology -e.g. PPLN sources with laser-written glass circuits [19,21] or III-V quantum dots with silica circuits [22] or with monolithic technology on PPLN [23][24][25][26], Silicium [18,20] or GaAs [27][28][29][30][31][32].…”