Abstract
Quantum correlated, highly non-degenerate photons can be used to synthesize disparate quantum nodes and link quantum processing over incompatible wavelengths, thereby constructing heterogeneous quantum systems for otherwise unattainable superior performance. Existing techniques for correlated photons have been concentrated in the visible and near-IR domains, with the photon pairs residing within one micron. Here, we demonstrate direct generation and detection of high-purity photon pairs at room temperature with 3.2 um wavelength spacing, one at 780 nm to match the rubidium D2 line, and the other at 3950 nm that falls in a transparent, low-scattering optical window for free space applications. The pairs are created via spontaneous parametric downconversion in a lithium niobate waveguide with specially designed geometry and periodic poling. The 780 nm photons are measured with a silicon avalanche photodiode, and the 3950 nm photons are measured with an upconversion photon detector using a similar waveguide, which attains 34% internal conversion efficiency. Quantum correlation measurement yields a high coincidence-to-accidental ratio of 54, which indicates the strong correlation with the extremely non-degenerate photon pairs. Our system bridges existing quantum technology to the challenging mid-IR regime, where unprecedented applications are expected in quantum metrology and sensing, quantum communications, medical diagnostics, and so on.
Highlights
We report on direct generation and measurement of correlated photons spaced by as much as 3.2 um, between 780 nm and 3950 nm, using only room temperature devices
Falling in a transparent window of the atmosphere with an acceptable background level of blackbody radiation, the 3950 nm photons are superior for free-space quantum communications under dynamic, scattering weather conditions, such as in urban or maritime environment
Our photon pairs are created through spontaneous parametric down conversion (SPDC) in a magnesium-doped periodically-poled lithium niobate (MgO:PPLN) waveguide
Summary
Yong Meng Sua[1,2], Heng Fan[1,2], Amin Shahverdi[1,2,3], Jia-Yang Chen1,2 & Yu-Ping Huang[1,2]. We report on direct generation and measurement of correlated photons spaced by as much as 3.2 um, between 780 nm and 3950 nm, using only room temperature devices Quantum correlation over such distant spectra can bridge the existing quantum photonic technology in visible and near-IR into the rarely-visited, challenging mid-IR regime, thereby enabling new domains of quantum operations. By using broadband, mode-shaped pumping pulses, it can selectively upconvert the signal photons over interfering noises that overlap in both time and spectrum[35] These unique capabilities offered by such upconversion detectors will prove crucial for photon-starving applications, such as free-space quantum communications and remote sensing, where the received signal is swamped by ambient photons.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
