ANU Open Research Repository has been upgraded. We are still working out a few issues, and there may be periodic outages throughout the day. Please get in touch with if you experience any issues.

Biphoton generation in quadratic waveguide arrays: A classical optical simulation




Gräfe, M
Solntsev, Alexander
Keil, Robert
Sukhorukov, Andrey
Heinrich, Matthias
Tünnermann, Andreas
Nolte, Stefan
Szameit, A
Kivshar, Yuri

Journal Title

Journal ISSN

Volume Title


Nature Publishing Group


Quantum entanglement became essential in understanding the non-locality of quantum mechanics. In optics, this non-locality can be demonstrated on impressively large length scales, as photons travel with the speed of light and interact only weakly with their environment. Spontaneous parametric down-conversion (SPDC) in nonlinear crystals provides an efficient source for entangled photon pairs, so-called biphotons. However, SPDC can also be implemented in nonlinear arrays of evanescently coupled waveguides which allows the generation and the investigation of correlated quantum walks of such biphotons in an integrated device. Here, we analytically and experimentally demonstrate that the biphoton degrees of freedom are entailed in an additional dimension, therefore the SPDC and the subsequent quantum random walk in one-dimensional arrays can be simulated through classical optical beam propagation in a two-dimensional photonic lattice. Thereby, the output intensity images directly represent the biphoton correlations and exhibit a clear violation of a Bell-like inequality.





Scientific Reports


Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights



Restricted until