Examination of acousto-optic interaction and infrared laser applications

Acousto-optic devices makes use of the electric drive signal to control the power of light. An acousto-optic device is based on the acousto-optic (photo-elastic) effect which dynamically changes refractive index of the medium by the oscillation of sound signal that causes mechanical stress. Acousto-optic devices are essential for temporal and spatial control of the high power lasers with high repetition frequencies, and they are one of the most effective solutions. In todays world, an acousto-optic device is extensively used in military and space, astronomy, telecommunication, industry, semiconductor and electronics, information technologies, health sector and more. Acousto-optic devices can be used for modulation, deflection, Q-switching, tunable filtering, frequency shifting and mode locking in optical applications esspecialy for the infrared region. This study composes of three main sections: the theory of acousto-optic interaction, principles of manufacturing of acousto-optic devices and modelling. There are considerable number of articles, books, and patents in acousto-optics field due to its wide history. In the first section, the theory of acousto-optic interaction is explained by making use of the literature, subsequently common materials used in acousto-optic devices are mentioned and the connection with the real-life applications is made. In the next section, the types of acousto-optic devices, operation principles of modulators and manufacturing steps followed are explained using the literature. After the theory of the acousto-optic interaction and the necessary details for the manufacturing of the devices are given, the basic parameters of the lasers in the infrared band are mentioned, and the two-dimensional acousto-optic and piezoelectric modeling studies are carried out. The analysis is made using Comsol Multiphysics application, which employs the finite element method. Using the created model, simulations are made and obtained results are interpreted. Besides, being used for modification of the time and frequency features of light, acousto-optic devices can also be used to shape the beam radiation profile. Some systems use expensive and area consuming optic elements while already utilizing an acousto-optic device. Finally, the previously created two-dimensional acousto-optic device model is used for the simulation of the beam shaping capability of acousto-optic devices in this type of systems. Simulations are made for converting a laser beam having a Gaussian radiation profile into a uniform radiation profile where the obtained results are examined.