Foundry technology and services for si photonics

We discuss the progress in development and offering of silicon photonic integration platforms based on 200mm and 300mm wafer technologies. Devices have capability for developing high-speed datacommunication, but are also used for life science applications

Proper general decomposition (PGD) for the resolution of Navier–Stokes equations

In this work, the PGD method will be considered for solving some problems of fluid mechanics by looking for the solution as a sum of tensor product functions. In the first stage, the equations of Stokes and Burgers will be solved. Then, we will solve the Navier–Stokes problem in the case of the lid-driven cavity for different Reynolds numbers (Re = 100, 1000 and 10,000). Finally, the PGD method will be compared to the standard resolution technique, both in terms of CPU time and accuracy.Région Poitou-Charente

Microcellular Foaming of Polymethylmethacrylate in a Batch Supercritical CO2 Process: Effect of Microstructure on Compression Behavior

Microcellular foaming of reinforced core/ shell Polymethylmethacrylate (PMMA) was carried out bymeans of supercritical CO2 in a single-step process. Samples were produced using a technique based on the saturation of the polymer under high pressure of CO2(300 bars,40 C), and cellular structure was controlled by varying the depressurization rate from 0.5 bar/s to 1.6 x10-2 bar/sleading to cell sizes from 1lm to 200l m, and densities from 0.8 to 1.0 g/cm3. It was found that the key parameter to control cell size was depressurization rate, and larger depressurization rates generated bigger cell sizes. On the other hand, variation of the density of the samples was not so considerable. Low rate compression tests were carried out, analyzing the dependence of mechanical parameters such as elastic modulus, yield stress and densification strain with cell size. Moreover, the calculation of the energy absorbed for each sample is presented, showing an optimum of energy absorption up to 50% of deformation in the micrometer cellular range (here at a cell size of about 5 µm). To conclude, a brief comparison between neat PMMA and the core/shell reinforced PMMA has been carried out, analyzing the effect of the core/shell particles in the foaming behavior and mechanical properties

Integrated photonic circuit in silicon on insulator for fourier domain optical coherence tomography

Optical coherence tomography (OCT) is a medical imaging technology capable of producing high-resolution, cross-sectional images through inhomogeneous samples, such as biological tissue. It has been widely adopted in clinical ophthalmology and a number of other clinical applications are in active research. Other applications of OCT include material characterization and non-destructive testing. In addition to current uses, OCT has a potential for a much wider range of applications and further commercialization. One of the reasons for slow penetration of OCT in clinical and industrial use is probably the cost and the size of the current systems. Current commercial and research OCT systems are fiber/free space optics based. Although fiber and micro-optical components have made these systems portable, further significant miniaturization and cost reduction could be achieved through the use of integrated photonic components. We demonstrate a Michelson interferometer using integrated photonic waveguides on nanophotonic silicon on insulator platform. The size of the interferometer is 1500 mu m x 50 mu m. The structure has been tested using a mirror as a reflector. We can achieve 40 mu m axial resolution and 25 dB sensitivity which can be substantially improved

Formar a los estudiantes en el método experimental : ¿Utopía o problema superado?

A laboratory work teaching sequence, based on the practical work objectives definition, on the progressive development of autonomy, and a hierarchized learning task is experimented. The evaluation of students results show that the learning strategies lead to a real mastery of experimental process