Researchers at NIST have successfully converted the wavelength of single photons emitted by quantum dots from near-infrared (1,300 nm) to near-visible (710 nm) using an up-conversion crystal and pump laser. This breakthrough could enable hybrid quantum systems for applications in quantum communication, computation, and metrology.
The process involves combining a fiber-coupled single photon source with a frequency up-conversion detector, both developed at NIST. The up-conversion detector uses a strong pump laser and non-linear crystal to efficiently convert long wavelength photons into shorter wavelengths with high sensitivity.
This wavelength conversion is important because it allows single photons to be transmitted over long distances using low-loss telecommunications fibers while still being easily detected with mature near-visible wavelength detectors. The technique could enable more efficient quantum information processing by combining the advantages of both near-infrared transmission and near-visible storage in quantum memories.
Keywords: Up-conversion, Single photon, Quantum dot, Wavelength conversion, Photon detection
