The present paper describes a new parametric design and optimization tool [Support Optimization and Design Tool (SODT)], used to evaluate passive axial support positions on circular solid meniscus mirrors. The developed tool avoids the intrinsic limitations of methodologies of the reference literature, based on analytical formulations. A parametric finite element model of the mirror is generated from the user inputs and the support distribution is optimized in terms of the root mean square of the surface error (SFE). The optimization process is based on a hybrid optimization algorithm combining genetic algorithms and a gradient-based approach. The results are compared to the ones presented in the literature, evidencing minor discrepancies that can be basically attributed to differences in methodology and structural formulation, as it is discussed in the text. Finally, the finite element and optical postprocessing results are verified against industry-grade software: MSC Nastran ® and Sigmadyne SigFit ® .

3D printing technologies experienced a huge evolution both in techniques and applications since its invention in the early 1980s. Fused Deposition Modelling (FDM) was the first term used to describe an additive manufacturing technique and from that point on, many different ways of 3D printing have been developed to fulfil a variety of needs. Nowadays, 3D printing has become more accessible to the general public because of the big drop in prices caused by the big technical developments. As a result of that, a community of “makers” has been taking shape internationally making access to designs and advice easier. 3D printing is without a doubt one of the key developments of the last decades and covers from highly technical research fields (like medicine-related investigations) to individual makers or even educational programs to encourage young people to create. As a result of that, it can be seen daily that the so-called 3D printing has gained a big amount of fame between fabrication processes for its accessibility and ease of use, it only takes a computer, a 3D printer and time. On behalf of that, an idea for a final degree thesis was proposed: designing and printing using fused deposition modelling a telescope for astronomical and educational purposes. The main goal of the project is to, first check the capabilities of the 3D printing technology to build telescopes for amateur astronomers, comparing its performance with the current commercial products, and secondly, to develop a set of educational resources that permit the easy construction of low-cost custom instruments for the teaching and diffusion of Astronomy and Space Science. The set of resources derived from this project will be an interesting tool for Astronomy beginners, Engineering and Science students, teachers, and makers. In this work, we summarise the current status of the project and the results obtained with the first built prototype, as well as the design and choices made to fulfil our needs in a practical and feasible way. Last but not least, a list of possible educational activities to be carried out with the developed resources will be exposed.

ABSTRACT:This work focuses on the description of two different techniques for characterizing wavefronts: by using Shack-Hartmann (SH) sensor and by using Point Diffraction Interferometer (PDI). Moreover describes application examples of each in recent research, and finally a comparative study of both techniques on a single optical system is performed.

Earth atmosphere turbulence affects many areas of interest related with Space studies, such as optical communications or Astronomy. In fact, it is a key topic for such applications and, thus, it is important for students in aerospace and aeronavigation studies to get some knowledge of the basis of such phenomena, and how to compensate for it. The phenomenon of turbulence is tangent to many areas such as Optics, Meteorology, Fluid Dynamics, Astronomy, Space Science and Telecommunications, among others. To properly understand the effect of such phenomena on the propagation of an optical signal is imprescindible to properly evaluate and implement the corrections introduced with Adaptive Optics [1] and for understanding the limitations of optical free-space communications channels. The simulation of optical propagation through turbulence constitutes an intuitive and powerful tool for visualizing and understanding such phenomena. Within those ideas, a Final Degree Project, based on the development of simulation tools of atmospheric turbulence is carried out in the Escola d’Enginyeria de Telecomunicacions i Aeroespacial de Castelldefels (EETAC) of the Universitat Politècnica de Catalunya (UPC). In this communication the development of an application, written in MATLAB®, for the simulation of optical propagation through turbulent mediums is presented. The project consists of the development of a software based on scalar diffraction theory [2] and Kolmogorov’s turbulence theory for the generation of turbulent phases under specific meteorological conditions and the simulation of the propagation of an electromagnetic signal through them. With this tool, different applications are going to be analysed. As an example of application, at the moment this communication is presented, the code is capable of performing the reconstruction of the generated phase in terms of Zernike coefficients [3], providing key information for the understanding of the aberrations introduced by the turbulence and also for correcting them with a proper design. The communication first describes the main basis of the problem, in terms of scalar diffraction theory, and the structure of the application. Later, some results are presented and discussed. Finally, the application of the tool for adaptive optics, optical free-space communications and as an educational application for aeronavigation and aerospace students is discussed, with emphasis in the context of the different degrees, courses and subjects taught in the EETAC.