Abstract
The potential of evanescent Mach-Zehnder interferometers, embedded in Eagle2000 substrates, as refractive index sensors was assessed. For that, femtosecond laser direct writing and wet etching were used to fabricate and expose the sensing arm at the surface of the glass substrate, while keeping the reference arm buried. From the analysis of the structures' spectral response, we found that the wavelength shift of the different order peaks increased greatly for refractive indices nearing that of the glass, indicating a greater overlap between the guided mode's evanescent field and the external medium. Therefore, a maximum sensitivity of 10271 nm/RIU was obtained at a refractive index of 1.491. The sensitivity in the refractive index range of water-based solutions was, on the other hand, limited to 446 +/- 39 nm/RIU. Due to the geometry of the device, applications with films deposited at the surface of the substrate and PDMS based microfluidic channels can be explored.

Abstract
Optical waveguides were fabricated at the surface of Eagle2000 glass substrates, using femtosecond laser direct writing and wet etching, and their potential as intensity-modulated refractometers was assessed. Through the analysis of their broadband spectral response to different refractive index oils, we observed that mode mismatch is present when the guided mode reaches the surface of the substrate and interacts with the external medium, thus enabling the use of such optical waveguides in refractive index sensing. Refractive indices equal to or greater than that of the substrate also induced a coupling mechanism that was shown not to be suitable in these devices. The device's wavelength of operation was found to be tunable by controlling the distance between the surface and the center of the optical waveguide. However, the sensitivity was seen to diminish by increasing the latter, being nonexistent for distances greater than 5.5 mu m. In this study, the maximum sensitivity values were found for a surface to core center distance between 1 and 2 mu m, in the biological range, and 2.5 to 3 mu m, for a refractive index nearing that of the substrate. Accordingly, maximum sensitivities of approximate to 25 dB/RIU and approximate to 1200 dB/RIU were found between 1.300 < n(D)(25)degrees(C) < 1.400 and 1.490 < n(D)(25)degrees(C) < 1.500, respectively.

Abstract
Low loss optical waveguides are the key component for the fabrication of more complex integrated optics devices. In most works related to femtosecond laser written waveguides, the values presented give results at a single wavelength or in a narrow wavelength band; but some applications in optical sensing, for example, would benefit from waveguides having good propagation properties in a larger wavelength range. This paper presents results that allow one to gain insight into the major loss mechanisms present in laser written waveguides in two different types of glasses (fused silica and Eagle 2000 glass) and the dependence of those on the fabrication parameters. Finally, an example of application of broadband operating waveguides is given.

Abstract
A monolithic lab-on-a-chip fabricated by femtosecond laser micromachining capable of label-free biosensing is reported. The device is entirely made of fused silica, and consists of a microdisk resonator integrated inside a microfluidic channel. Whispering gallery modes are excited by the evanescent field of a circular suspended waveguide, also incorporated within the channel. Thermal annealing is performed to decrease the surface roughness of the microstructures to a nanometric scale, thereby reducing intrinsic losses and maximizing the Q-factor. Further, thermally-induced morphing is used to position, with submicrometric precision, the suspended waveguide tangent to the microresonator to enhance the spatial overlap between the evanescent field of both optical modes. With this fabrication method and geometry, the alignment between the waveguide and the resonator is robust and guaranteed at all instances. A maximum sensitivity of 121.5 nm/RIU was obtained at a refractive index of 1.363, whereas near the refractive index range of water-based solutions the sensitivity is 40 nm/RIU. A high Q-factor of 10(5) is kept throughout the entire measurement range.

Abstract
Background: This study aims to evaluate food waste and menu quality in two canteens (A and B) from a Portuguese public university in order to identify challenges and opportunities to improve the food service. Methods: Food waste included the analysis of two canteens over 5 consecutive days by selective aggregate weighing. A qualitative evaluation of a 5-week menu cycle related to lunches was performed through the Qualitative Evaluation of Menus (AQE-d) method. Results: Both menus have "satisfactory " evaluations and lower adequacy to the dietary guidelines in criteria A, which evaluates general items from the dish, and in criteria B, which evaluates meat, fish and eggs. The calculated mean of food waste in both canteens exceeded the acceptable limit of 10%, except for the vegetarian (7.5%) dish in canteen A. The biggest waste was found in the vegetarian dish (16.8%) in canteen A. In meat dishes the conduit presents more waste (17.0%) than in fish and vegetarian dishes. Among these, the vegetables were the most wasted (25.3% and 27.9%, respectively). Conclusion: This work presents some insights to future interventions in the direction of a healthier and more sustainable foodservice.

Abstract
In this work we use the concept of paraxial fluids of light to explore quantum turbulence, probing a turbulent regime induced on an optical beam propagating inside a defocusing nonlinear media. For that purpose, we establish a physical analogue of a two-component quantum fluid by making use of orthogonal polarizations and incoherent beam interaction, obtaining a system for which the perturbative excitations follow a modified Bogoliubov-like dispersion relation. This dispersion relation features regions of instability that define an effective range of energy injection and that are easily tuned by manipulating the relative angle of incidence between the two components. Our numerical results support the predictions and show evidence of direct and inverse turbulent cascades expected from weak wave turbulence theories, which may inspire new ways to explore to quantum turbulence with optical analogues.