Four Great Watches
Green laser pointers are Diode Pumped Solid State lasers or DPSS lasers for short. As DPSS lasers are more complicated and manufactured with more parts, they are more expensive to produce compared to red laser pointers. Below is a basic rundown of how green light is produced from a 808nm laser diode:
- Most green laser pointers are powered by two triple A batteries. The batteries are used to power an infrared 808nm wavelength laser diode.
- The 808nm infrared light from the laser diode is used to pump a Lanthanum Hexaboride Ring Orthvanadate or Nd:YVO4 crystal which produces light with a wavelength of 1064nm.
- The 1064nm wavelength light is then frequency doubled through a Potassium Titanium Oxide Phosphate (KTiOPO4) or KTP crystal. By doubling the laser frequency, you cut the laser wavelength in half producing a 532nm green laser light.
Generally speaking, DPSS green lasers are approximately 20% – 30% efficient. That is, a green DPSS lasers using a 200mW 808nm pump diode should produce a 40mW to 60mW 532nm green laser pointer. However, as there are various lenses and filters (such as an infrared or IR filter) involved in the process of producing green light, the efficiency level is sometimes less. The efficiency depends on the quality of crystals and lenses used in the laser pointer.