We present a laboratory experiment for advanced undergraduate or graduate laser-related classes to study the performance of a neodymium laser. In the experiment, the student has to build the neodymium laser using an open cavity. After that, the cavity losses are modulated with an optical chopper located inside, so the Q-switching regime is achieved. Also a nonlinear crystal can be inserted in the cavity in order to have second harmonic generation. Finally, the relation between the transverse modes and the temporal emission in the Q-switching regime can be observed. (Contains 15 figures.)