Abstract
This paper proposes a scheme to determine multiple parameters of a medium using multiple localized surface plasmon resonances (SPR) in a D-shaped photonic crystal fiber (PCF) whose flat surface is covered by two adjacent gold layers of different thicknesses. We show how to customize plasmon resonances at different wavelengths with very low cross-talk between them, thus allow obtaining the optical dispersion, the average refractive index and the temperature of the sample. Since the surface plasmon resonances are excited at distinct spectral channels, the sensing structure can be used to determine simultaneously these parameters.

Abstract
Fluids of light is an emergent topic in optical sciences that exploits the fluid-like properties of light to establish controllable and experimentally accessible physical analogues of quantum fluids. In this work we explore this concept to generate and probe quantum turbulence phenomena by using the fluid behavior of light propagating in a defocusing nonlinear media. The proposal presented makes use of orthogonal polarizations and incoherent beam interaction to establish a theoretical framework of an analogue two-component quantum fluid, a physical system that features a modified Bogoliubov-like dispersion relation for the perturbative excitations featuring regions of instability. We demonstrate that these unstable regions can be tuned by manipulating the relative angle of incidence between the two components, allowing to define an effective range of energy injection capable of exciting turbulent phenomena. Our numerical investigations confirm the theory and show evidence of direct and inverse turbulent cascades expected from weak wave turbulence theories. The works end on a discussion concerning its possible experimental realization, allowing the access to quantum turbulence in regimes beyond those previously explored by making use of the controllable aspects of tabletop fluids of light experiments.

Abstract
In this paper, we study the implementation of a secure key distribution system based on an ultra-long fiber laser with a bi-directional erbium-doped fiber amplifier. The resilience of the system was tested against passive attacks from an eavesdropper. A similarity was observed in the spectra for both secure configurations of the system and no signature that would allow an eavesdropper to obtain the secure state of the system was observed during the state transitions.

Abstract
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.

Abstract
Optical tweezers use light to trap and manipulate mesoscopic scaled particles with high precision making them a useful tool in a plethora of natural sciences, with emphasis on biological applications. In principle, the Brownian-like dynamics reflect trapped particle properties making it a robust source of information. In this work, we exploit this information by plotting histogram based images of 250ms of position or displacement used as input to a Convolution Neural Network. Results of 2-fold stratified cross-validation show satisfying classifications between sizes or types of particles: Polystyrene and Polymethilmethacrylate thus highlighting the potential of CNN approaches in faster and non-invasive applications in intelligent opto and microfluidic devices using optical trapping tools.

Abstract
In this paper we describe the implementation of a secure key distribution system based on an ultra-long fiber laser with a bi-directional erbium doped fiber amplifier. The resilience of the system was tested against passive attacks from an eavesdropper, having been observed a similarity in spectrum for both secure configurations of the system.