Educational experimental setup based on laser beam scanners

Abstract

We present a simple experimental setup based on two optical scanners to control a laser beam for a series of educational experiments. It was verified that this simple design, broadly used for spectacular laser-show presentations, can also significantly help the educational process for interested in physics undergraduate students mainly of art orientations, which might have a lower scientific or technological background. Comparison with an oscilloscope proved that the system accurately replicates the oscilloscope output (Lissajous figures), when two sinusoidal signals of various frequencies and phases are used as inputs. The Lissajous figures are demonstrated on the lab wall as a spectacular image that attracts the interest of the students to further study the underlying phenomena, without any need to educate them on complicated instruments such as oscilloscopes. The experiment awakens an additional motivation to study several issues related to laser radiation such as the scattering of the beam in the air, laser intensity and it is useful as an introductory experiment before presenting double-slit interference or direction of light experiments. Additionally, it can be used to measure the frequency of an unknown acoustic signal generated by a tuning fork, the phase difference between two signals and the wavelength and the velocity of sound.