Play optics with LEGO

The basic elements of a fairly complete optomechanical kit based on the use of LEGO(a) is presented. Through a careful exploitation of the many standard LEGO elements, and adding a few new simple components made of plexiglass, we demonstrate that almost all of the mechanical parts of an optical setup can be built with little effort and at an extremely reduced cost. Several systems and experiments are presented, mainly in the fields of optical filtering and interferometry, to show that the proposed mountings are perfectly suitable for didactic purposes, and can often be employed even in more demanding scientific applications.