Abstract: A co/counter propagating acousto-optic modulator is provided that creates a low-intensity focused ultrasound (FUS) wave on a laser beam in a medium such as water without any auxiliary mediators or special software/hardware. The main optical effect of the FUS is the controllable focusing of the laser beam through modification of the refractive index of the medium in a time-stable and dynamic fashion. The laser beam and the FUS wave are coaxially mixed and propagated through each other. The FUS pressure field highly amplifies the power density, highly amplifies the intensity, sharpens the diameter, and reduces the full width at half maximum (FWHM) of the laser beam. The FUS pressure field keeps the laser beam's lensing power positive, with small fluctuations, as long as the ultrasound wave is coaxially propagated with the laser beam.

Abstract: A co/counter propagating acousto-optic modulator is provided that creates a low-intensity focused ultrasound (FUS) wave on a laser beam in a medium such as water without any auxiliary mediators or special software/hardware. The main optical effect of the FUS is the controllable focusing of the laser beam through modification of the refractive index of the medium in a time-stable and dynamic fashion. The laser beam and the FUS wave are coaxially mixed and propagated through each other. The FUS pressure field highly amplifies the power density, highly amplifies the intensity, sharpens the diameter, and reduces the full width at half maximum (FWHM) of the laser beam. The FUS pressure field keeps the laser beam's lensing power positive, with small fluctuations, as long as the ultrasound wave is coaxially propagated with the laser beam.