Abstract The conversion and interaction between quantum signals at a single-photon level are essential for scalable quantum photonic information technology. Using a fully-optimized, periodically-poled lithium niobate microring, we demonstrate ultra-efficient sum-frequency generation on chip. The external quantum efficiency reaches (65±3)% with only (104±4) uW pump power, improving the state-of-the-art by over one order of magnitude. At the peak conversion, 3×10-5 noise photon is created during the cavity lifetime, which meets the requirement of quantum applications using single-photon pulses. Using pump and signal in single-photon coherent states, we directly measure the conversion probability produced by a single pump photon to be 10-5---breaking the record by 100 times---and the photon-photon coupling strength to be 9.1 MHz. Our results mark a new milestone toward quantum nonlinear optics at the ultimate single photon limit, creating new background in highly integrated photonics and quantum optical computing.
Abstract The conversion and interaction between quantum signals at a single-photon level are essential for scalable quantum photonic information technology. Using a fully-optimized, periodically-poled lithium niobate microring, we demonstrate ultra-efficient sum-frequency generation on chip. The external quantum efficiency reaches (65±3)% with only (104±4) uW pump power, improving the state-of-the-art by over one order of magnitude. At the peak conversion, 3×10-5 noise photon is created during the cavity lifetime, which meets the requirement of quantum applications using single-photon pulses. Using pump and signal in single-photon coherent states, we directly measure the conversion probability produced by a single pump photon to be 10-5---breaking the record by 100 times---and the photon-photon coupling strength to be 9.1 MHz. Our results mark a new milestone toward quantum nonlinear optics at the ultimate single photon limit, creating new background in highly integrated photonics and quantum optical computing.
The conversion and interaction between quantum signals at the single-photon level are essential for scalable quantum photonic information technology. Using a fully optimized periodically poled lithium niobate microring, we demonstrate ultraefficient sum-frequency generation on a chip. The external quantum efficiency reaches $(65\ifmmode\pm\else\textpm\fi{}3)\mathrm{%}$ with only $(104\ifmmode\pm\else\textpm\fi{}4)$-$\ensuremath{\mu}\mathrm{W}$ pump power. At peak conversion, $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$-noise photon is created during the cavity lifetime, which meets the requirement of quantum applications using single-photon pulses. Using a pump and signal in single-photon coherent states, we directly measure the conversion probability produced by a single pump photon to be ${10}^{\ensuremath{-}5}$, which is a significant improvement from the state of the art, and the photon-photon coupling strength to be 9.1 MHz. Our results mark steady progress toward quantum nonlinear optics at the ultimate single-photon limit, with potential applications in highly integrated photonics and quantum optical computing.
We demonstrate parametric all-optical modulation in a periodically-poled lithium niobate microring resonator on chip. It employs quantum Zeno blockade between two distinct waves, a signal and a pump, through their sum-frequency generation at a large per-photon efficiency of 8.2 MHz. With nanosecond pump pulses at 6 mW peak power, 85.7% modulation extinction is observed, marking over 30~times efficiency improvement across various previous implementations. With only 2 mW pump peak power, 43.0% modulation extinction is observed for a doubly-stronger signal at 4 mW. This demonstrates, for the first time, that optical transistors with cascadability and fan-out are possible with just parametric nonlinear optics. These results, together with inherent advantages in such photonic integrated circuits, open the door to scalable technology for all-optical and quantum information processing.
Quantum photon sources of high rate, brightness, and purity are increasingly desirable as quantum information systems are quickly scaled up and applied to many fields. Using a periodically poled lithium niobate microresonator on chip, we demonstrate photon-pair generation at high rates of 8.5 and 36.3 MHz using only 3.4 and 13.4 μW pump power, respectively, marking orders of magnitude improvement over the state of the art, across all material platforms. These results constitute the first direct measurement of the device's giant single photon nonlinearity. The measured coincidence to accidental ratio is well above 100 at those high rates and reaches 14682±4427 at a lower pump power. The same chip enables heralded single-photon generation at tens of megahertz rates, each with low autocorrelation g_{H}^{(2)}(0)=0.008 and 0.097 for the microwatt pumps, which marks a new milestone. Such distinct performance, facilitated by the chip device's noiseless and giant optical nonlinearity, will contribute to the forthcoming pervasive adoption of quantum optical information technologies.
We report on multiphoton statistics of correlated twin beams produced in a periodic poled microring resonator on thin-film lithium niobate. Owing to high-cavity confinement and near-perfect quasi-phase-matching, the photon pairs are produced efficiently in single modes at rates reaching 27 MHz per $\text{\ensuremath{\mu}}\mathrm{W}$ pump power. By using a pump laser whose pulse-width impedance matches with the cavity, those photons are further created in single longitudinal modes with purity reaching 99%, without relying on later-on filtering. With a dual-channel photon-number-resolving detection system, we obtain directly the joint detection probabilities of multiphoton states up to three photons, with high coincidence to accidental contrast for each. Used as a single-photon source, it gives heralded gH(2)(0) around 0.04 at a single-photon rate of 650 kHz on chip. The findings of our research highlight the potential of this nanophotonic platform as a promising platform for generating nonclassical, few-photon states with ideal indistinguishability, for fundamental quantum optics studies and information applications.
We report on multi-photon statistics of correlated twin beams produced in a periodic poled micro-ring resonator on thin-film lithium niobate. Owing to high cavity confinement and near perfect quasi-phase matching, the photons pairs are produced efficiently in single modes at rates reaching 27 MHz per μW pump power. By using a pump laser whose pulse width impedance matches with the cavity, those photons are further created in single longitudinal modes with purity reaching 99\%, without relying on later-on filtering. With a dual-channel photon-number resolving detection system, we obtain directly the joint detection probabilities of multi-photon states up to three photons, with high coincidence to accidental contrast for each. Used as a single photon source, it gives heralded gH(2)(0) around 0.04 at a single photon rate of 650 kHz on chip. The findings of our research highlight the potential of this nanophotonic platform as a promising platform for generating non-classical, few-photon states with ideal indistinguishability, for fundamental quantum optics studies and information applications.
Quantum frequency conversion (QFC) plays a crucial role in constructing seamless interconnection between quantum systems operating at different wavelengths. To advance future quantum technology, chip-scale integrated QFC components, featuring high efficiency, small footprint, low power consumption, and high scalability, are indispensable. In this work, we demonstrate the first hybrid integrated QFC chip on a thin-film lithium niobate platform that connects the telecom and visible bands. Benefiting from the periodically poled microring resonator with ultra-high normalized conversion efficiency of 386,000%/W, an ultra-low pump power of 360 μW is achieved, which is more than two orders of magnitude lower than the traditional straight waveguide scheme. By injecting current into the chip, an on-chip quantum efficiency of 57% and a noise count of ∼7000 counts per second are achieved. Such an electrically pumped, integrated, and scalable QFC chip would significantly advance the integration of quantum networks and the development of chip-scale quantum optical systems.