Schematic diagram of a Michelson-like interferometer used to explore the coherence length of the diode-pumped solid-state laser. m ₂ and m ₃: fixed mirrors as in Figure 1. m ₅: manually movable mirror. BS: polarizing beam splitter. L ₃: lens. OS: observation screen. c ₂: camera. The images were labelled with the arm used to interfer. A video of this experiment showing the interferences is available in Suppl4.mp4.