532nm and 520nm are two common wavelengths of green light. What is the difference between these two laser module? Their green light is very similar, but the 520nm is more like grass green. The working principles of the 532nm and 520nm green lasers are also different. The 532nm laser is produced by the frequency doubling of the laser crystal. The 520nm laser is generated by a semiconductor laser diode. These two lasers have different spot modes. The 532nm laser is a TEM00 laser, and the beam quality is better. Let’s check it now.