Generation of highly pure single-photon state at telecommunication wavelength
Akito Kawasaki, Kan Takase, Takefumi Nomura, Sigehito Miki, Hirotaka Terai, Masahiro Yabuno, Fumihiro China, Warit Asavanant, Mamoru Endo, Jun–ichi Yoshikawa, Akira Furusawa
Abstract
Telecommunication wavelength with well-developed optical communication technologies and low losses in the waveguide are advantageous for quantum applications. However, an experimental generation of non-classical states called non-Gaussian states at the telecommunication wavelength is still underdeveloped. Here, we generate highly-pure-single-photon states, one of the most primitive non-Gaussian states, by using a heralding scheme with an optical parametric oscillator and a superconducting nano-strip photon detector. The Wigner negativity, the indicator of non-classicality, of the generated single photon state is -0.228 ± 0.004, corresponded to 85.1 ± 0.7% of single photon and the best record of the minimum value at all wavelengths. The quantum-optics-technology we establish can be easily applied to the generation of various types of quantum states, opening up the possibility of continuous-variable-quantum-information processing at the telecommunication wavelength.