Quantum entanglement and interference at 3 μm
Zheng Ge, Zhao-Qi-Zhi Han, Fan Yang, Xiao-Hua Wang, Yin‐Hai Li, Yan Li, M. Gao, Renhui Chen, Sujian Niu, Mengyu Xie, Zhi‐Yuan Zhou, Bao-Sen Shi
Abstract
Given the important advantages of the mid-infrared optical range (2.5 to 25 μm) for biomedical sensing, optical communications, and molecular spectroscopy, extending quantum information technology to this region is highly attractive. However, the development of mid-infrared quantum information technology is still in its infancy. Here, we report on the generation of a time-energy entangled photon pair in the mid-infrared wavelength band. By using frequency upconversion detection technology, we observe the two-photon Hong-Ou-Mandel interference and demonstrate the time-energy entanglement between twin photons at 3082 nm via the Franson-type interferometer, verifying the indistinguishability and nonlocality of the photons. This work is very promising for future applications of optical quantum technology in the mid-infrared band, which will bring more opportunities in the fields of quantum communication, precision sensing, and imaging.