The idea of our experiment is to produce Lissajous figures
by modulating a laser beam in two perpendicular directions
using two tuning forks that vibrate independently. We used
two identical aluminum tuning fork sets from PASCO SE-
7342. Each set includes eight forks representing a full octave
of frequencies. The experimental setup is shown in Fig.
1. The two tuning forks are mounted on a table at 90° to each
other. The degree of orthogonality is not very important for
our purpose, so was done just by eye. The distance between
them was 60 cm.