Double acousto-optic deflector system for increased scanning range of laser beams

A new laser scanning system is presented based on two wide-band acousto-optic deflectors. The interaction medium is tellurium dioxide. Anisotropic interactions take place under two different tangential phase matching configurations in such a way that the acousto-optic bandwidths add up. We demonstrate the feasibility of such a cascade deflection system for the wavelength of λ = 514 nm. The total frequency bandwidth is Δf = 100 MHz, equally distributed between the two acousto-optic deflectors. The total angular scan at the output is Δθ = 4.4° leading to 125 resolvable spots for a 1 mm truncated Gaussian beam.