This apparatus is meant for graduate and post graduate level courses in physics. In this case, diffraction pattern is closely studied using a detector mounted on translation stage. The intensity is noted at closed intervals by traversing the detector through the cross section of the spectrum. The intensity versus distance curve is plotted on a graph for calculations.

The device consists of 1 meter long optical rail. At one end of the rail, X translation stage with detector is mounted and at the other end, laser is held on a kinematic mount. Linear scale attached to the rail makes distance measurement easy and convenient. Both the laser head and detector stage are mounted on rail carriages with locks, which in turn can be mounted anywhere on the rail conveniently.