Abstract
The fabrication of optical add-drop multiplexers in fused silica is demonstrated, for the first time to our knowledge, using the femtosecond laser direct writing technique. To achieve this, a Mach-Zehnder interferometer configuration was used for the signal routing by the implementation of 3-dB directional couplers, along with Bragg grating waveguides for wavelength selectivity. The fabrication of all individual devices required was optimized. The behavior of the fabricated add-drop multiplexer was characterized at around 1550 nm, where a 3-dB bandwidth of 0.19 +/- 0.01 nm was obtained along with an intrachannel and adjacent interchannel crosstalk of -30 and -20 dB at Delta lambda = +/- 0.75 nm, respectively. This study shows that such complex devices can be manufactured by femtosecond laser direct writing, with future improvements being discussed.

Abstract
This paper presents a multimode fiber sensor that uses surface plasmon resonance on a metallic wire to measure refractive index. Numerical simulations based on the finite element method reveal the sensor supports several plasmon modes in the wire capable of coupling with the multiples optical fiber modes. Therefore, the sensor configuration creates multiple resonances at different wavelengths, with different values of the loss, sensitivity, among other parameters. Choosing the appropriate mode and filtering out the rest of the modes allows to optimize the sensor performance. In the present work a sensitivity of 5340nm/RIU and resolution of 1.87x10(-6) RIU were found.

Abstract
Using the finite element method (FEM), this paper presents a numerical investigation of the performance analysis of a D-type photonic crystal fiber (D-type PCF) for refractive index sensing, based on surface plasmon resonance (SPR) with a planar structure made out of a metamaterial. COMSOL Multiphysics was used to evaluate the design of the referred refractive index optical fiber sensor, with higher accuracy and considerable economy of time and resources. A study of different metamaterials concentrations conformed by aluminum oxide (Al2O3) and silver (Ag) is carried out. Another structural parameters, which influences the refractive index sensor performance, the thickness of the metamaterial, is also investigated. The results indicate that the use of metamaterials provides a way of improving the performance of SPR sensors on optical fibers and allows to tailor the working parameters of the sensor.

Abstract
We propose a refractive index sensor based on surface plasmon resonance (SPR) in a gold wire partially incrusted on the surface of a D-type fiber and in contact with the external medium for increased sensitivity and roughness. The sensor is studied using numerical simulations based on the finite element method (FEM) and is compared with a more conventional D-type fiber SPR where the wire is replaced with a gold film. The numerical work estimates the sensitivity and resolution for different analytic refractive indexes (RI) in the range of 1.30-1.40, for a sensor based on the wavelength interrogation method. The results indicate that the use of the gold wire provides a better sensitivity when compared with the gold film, while supporting multiple peaks in different wavelengths, each with distinct values of sensitivity and resolution.

Abstract
The realization of tabletop optical analogue experiments of superfluidity relies on the engineering of suitable optical media, with tailored optical properties. This work shows how quantum atomic optical systems can be used to develop highly tunable optical media, with localized control of both linear and nonlinear susceptibility. Introducing the hydrodynamic description of light, the superfluidity of light in these atomic media is investigated through GPU-enhanced numerical simulations, with the numeric observation of the superfluidic signature of suppressed scattering through a defect.

Abstract
Under specific conditions, there is a formal analogy between the fundamental equations of electromagnetism and relativistic gravitation, described by the Einstein field equations of general relativity. In this paper, we report on how we have used this analogy to implement a solver of the Einstein equations adapting algorithms initially developed for electromagnetism, combined with methods of heterogeneous supercomputing, in GPU that can achieve fast computing and exhibit good performance. We also present the results of the simulations used to validate our solver. © 2017 SPIE.