The first successful development of silicon-based guided mode quantum integrated optical chip

China University of Science and Technology Key Laboratory of Quantum Information Ren Renfeng Research Group and Professor Dai Daizhe Zhejiang University cooperation, the first successful development of silicon-based waveguide quantum integrated chip. Results recently published in "Nature - Communications." Integrated optical devices and systems with small size, scalable, low power consumption, high stability and many other advantages, in the field of classical optical and quantum information attention. In the past, the research on integrated quantum optical chips usually adopted the degree of freedom of polarization or path freedom. Among them, the polarization coding has obvious deficiencies in the information capacity and security; the path coding spacing is usually large, which restricts the improvement of quantum optical chip integration and function expansion. Ren Xifeng and his collaborators for the first time proposed to adopt multiple eigenwave modes in wide waveguides as a new degree of freedom for encoding quantum information. It is expected to achieve high-dimensional quantum information coding using a multi-mode waveguide supporting multiple waveguide modes. Using the new silicon on-chip waveguide mode converter and waveguide mode multiplexer, they successfully achieved any coherent transition between polarization, path and waveguide mode degrees of freedom with single-photon and two-photon interference visibility of more than 90% The possibility of simultaneously manipulating multiple degrees of freedom in an integrated quantum optical chip lays an important foundation for realizing the high-dimensional quantum information process in an integrated quantum optical chip.