Brightest Laser Pointer for Outdoor Use?
A laser pointer is a bright source of light but so is the Sun. 🙂 The maximum legal limit for power output from any laser pointer in the USA is 5 mW – Class IIIa (there may also be more restrictive local regulations and it’s lower in some other countries). The best color to use is green since the wavelength of modern green laser pointers based on Diode Pumped Solid State (DPSS) laser technology (532 nm) is very near the peak of human visual sensitivity (555 nm). Thus, a 5 mW green laser pointer produces nearly the brightest beam allowable by law (about 0.9 relative to 555 nm). (Although older green laser pointers based on green helium-neon lasers were a bit closer at 543.5 nm, one capable of 5 mW would be almost a meter long and weigh several kilograms with the required backpack mounted battery and high voltage power supply.) Whether the beam is pulsed or continuous doesn’t make much difference. However, the spot from a low divergence beam may be somewhat more visible at a distance on
