Abstract: Systems embodying the invention include an arm having a polished mirror-like surface located on the arm. The arm includes means for mounting the arm on a shaft (or spindle) to allow the arm to rotate freely in the lateral direction (perpendicular to the length of arm). The arm is intended for use in a system which includes means for directing a beam of light onto the mirror-like surface whereby when the mirror-like surface is rotated (e.g., by Beta degrees) the beam of light reflected from the mirror-like surface is swept through a proportionate number of (e.g., 2 Beta) degrees. An electrically controllable system is coupled to the arm causing the arm to move in one direction and then in the opposite direction whereby the arm is caused to vibrate (oscillate) back and forth.