Laser beam Steering According to Linear Trajectories Using an Acousto-Optic Cell

When two frequency modulated acoustic waves propagate perpendicularly in an optically transparent medium, a two-dimensional periodic modulation of the refractive index is produced. This leads to split and steer the laser beam according to three axes (X,Y , ?). Adding a phase of p to one of these two acoustic waves permits to change the ? oscillation axis with an angle of p /2. Furthermore, the slope of this axis increases proportionally as a function of the ratio of two frequency excursions, which makes it possible to create an infinite number of linear trajectories. This technique is very flexible and should be useful for laser beam steering.