Simulación del efecto Optoacústico para identificar las características físicas de la interacción de un láser pulsado con una estructura morfológica.

Abstract

The optoacoustic effect occurs as a result of the interaction of a pulsed laser with a structure, where part of the absorbed energy is converted into thermal energy producing a temperature variation in the sample, which varies with the same frequency that makes radiation incident a driving force of change which simultaneously generates acoustic waves that can be detected by an ultrasonic transducer. The ANSYS software used the finite element method to test the optoacoustic effect in silic. The resercher took data from the experiment that allowed them to bring the results to the represented reality by the interaction of a beam with a biological element. Water was used as the aqueous médium in tank of negligible optical properties. A laser light source at 1064 nm wavelength with a pulse time of 10 ns (τ_p), and energy for this analysis by pulse 20 μJ (E0). The radiation area of 1 mm (rspot), this structure is directly related to the water content in the human body. Based on the basic optical principles, the relation of the initial and final conditions of the laser as an initial intensity I_0= 2000 W and a final intensity I=1131.051 W result of the absorbed energy E_abs=8.690 μJ where a part is transformed into thermal energy E_th=2.803 x 〖10〗^(-5) J/〖cm〗^3 were established. From these simulations termal confinement results were achieved in the order of 6.699 x 〖10〗^(-3) °C, which generates a pressure variation in the médium with measurable quantity in the range of 5.606x〖10〗^(-3) Pa. Optoacoustic research consists of an expanding fiel of knowledge where science and technology interact. Understanding the principle of optoacoustic generation turns out to be important to applications such in spectroscopy, analysis of thermoelastic properties of matter, microscopy, images, and the deactivation process study of states, among others.