Estudio de radiación láser en sistemas de micropartículas de silica y de microbacterias usando la técnica de pinza óptica en el laboratorio de óptica de la Facultad de Ciencias - ESPOCH

Abstract

The aim of this project was to study the effect of laser radiation and the Gaussian behaviour of the beam on systems of silica microparticles and microbacteria with a diameter of between 1 and 1 0 μm; several samples of silica and microbacteria were prepared and placed in the optical tweezers in the optics laboratory of the Faculty of Science at ESPOCH, with the aim of obtaining an optimal working methodology and to outline the appropriate physical principles to achieve the capture and manipulation of microparticles. It was identified that the optical beam regime is ideal for our experimentation. Once this was defined, we delved into the study and behaviour of the Gaussian beam in a 640 ƞm red laser, which we decided to use as it had the necessary characteristics. With this background, the experimental process was carried out by developing the physical assembly of the optical tweezers in the laboratory, describing in detail each of its constituent components, with emphasis on the focusing and observation area. Once the whole system was calibrated and the image capture technique was known by means of digital software connected to a CCD camera, we were able to see the interaction of the laser with the samples made, to be able to analyse them later. The results obtained could be better observed in the system of microbacteria obtained in a sample of stagnant water where the phenomenon of optical capture could be appreciated. With everything described in our project, we conclude that the capture of microparticles is a viable project that can be developed in the laboratories of the institution, using this research as a base model for future studies on the interaction of laser radiation in biological systems, or microscopic objects. It is recommended that specific and necessary components be purchased for the optical tweezers to operate effectively.