Towards the experimental observation of turbulent regimes and the associated energy cascades with paraxial fluids of light

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Ferreira, TD (Author) Other; Rocha, V (Author) Other; Silva, D (Author) Other; Guerreiro, A (Author) FCUP; Silva, NA (Author) Other

Journal

Title: New Journal of Physics

Vol. 24

ISSN: 1367-2630

Publisher: Institute of Physics Publishing

Indexing

ISI Web of Knowledge - 0 Citations

Scopus

Other information

Authenticus ID: P-00X-G0V

DOI: 10.1088/1367-2630/aca49a

Abstract (EN): The propagation of light in nonlinear optical media has been widely used as a tabletop platform for emulating quantum-like phenomena due to their similar theoretical description to quantum fluids. These fluids of light are often used to study two-dimensional phenomena involving superfluid-like flows, yet turbulent regimes still remain underexplored. In this work, we study the possibility of creating two-dimensional turbulent phenomena and probing their signatures in the kinetic energy spectrum. To that end, we emulate and disturb a fluid of light with an all-optical defect using the propagation of two beams in a photorefractive crystal. Our experimental results show that the superfluid regime of the fluid of light breaks down at a critical velocity at which the defect starts to exert a drag force on the fluid, in accordance with the theoretical and numerical predictions. Furthermore, in this dissipative regime, nonlinear perturbations are excited on the fluid that can decay into vortex structures and thus precede a turbulent state. Using the off-axis digital holography method, we reconstructed the complex description of the output fluids and calculated the incompressible component of the kinetic energy. With these states, we observed the expected power law that characterizes the generated turbulent vortex dipole structures. The findings enclosed in this manuscript align with the theoretical predictions for the vortex structures of two-dimensional quantum fluids and thus may pave the way to the observation of other distinct hallmarks of turbulent phenomena, such as distinct turbulent regimes and their associated power laws and energy cascades.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10