With the optoacoustic phenomenon, we can affect parts of the material deep below the irradiated surface. This converts the energy of the laser light into pressure waves, which propagate inside. By focusing the waves, locally large amplitudes are achieved, which has great potential in the field of medicine. The problem with existing systems is the lack of a simple and efficient focusing method that would allow the depth and size of the focused acoustic field to be dynamically changed. For this purpose, we developed a prototype optoacoustic lens where we applied a composite to a flat glass substrate on one side and made an annular copper mask on the other. The lens was immersed in water, where it was illuminated with laser pulses and the resulting pressure waves were measured with a hydrophone. The same model was defined in the Ansys APDL program and numerical analyses were performed. Experimental and numerical results were analyzed and compared, which showed a partial match. Through simulations and experiments, we have gained an in-depth understanding of the operation of a flat optoacoustic lens.
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