A green 5mw laser pointer is becoming the most popular laser pointer today. The reasons are because of its low price, and powerful beam. They first hit the stores in 2000, and because of their popularity, have become more affordable as time progresses.

The beam itself is generated by what is called a diode pumped solid state frequency doublers or DPSSFD. This is a more complicated laser unit since there is not a diode that can produce a laser in this wavelength region. Because of this, the production of the beam is done in an indirect way.

The beam that is generated is at 808 nm. This is done with an AlGaAs laser diode that channels the light into a crystal of neodymium doped yttrium aluminum vanadate, which changes the beam to a frequency of 1064nm. The crystal has a tendency to heat up so it is mounted to a copper heatsink. The beam is then channeled into another crystal of potassium titanyl phosphate which is also mounted on a heat sink that is in the laser’s resonator.

The two crystals must be properly aligned so the beam can be halved to 532mn. The more expensive models have an IR filter on the mirror, to reduce the amount of IR light that is produced from leaving the unit.  But as a cost-saving measure, this has been removed to reduce the final price of the laser pen.

Since their first introduction, there have been improvements. To increase the battery life and reduce the heat buildup, many of these lasers operate in the pulse or quasi continuous wave mode.

This laser can be seen in direct sunlight and at night. The uses include planet watching and pointing, along with firearms’ sighting, and of course, for presentations. The green 5mw laser pointer is the most powerful low-cost laser presently on the market.