Is it safe for the laser pointer to run 5V

Projects General Guidance
1

I just receive a 2x AA 1.5v Green Laser Pointer Max Output power: 5mW
Wave length approx.: Green: 523nm and I came with the idea to run it with 5v or 7v and I thinking wether this will destroy the laser diode because it cause heat, and what are good heat sink do you suggest to reduce the heat for this laser pointer?

2

It probably will destroy the laser diode or some other part of the internal circuitry. Why would you like to do so anyway? I guess it will run without a problem if you provide 3.3V to it.

3

It's impossible to know...

If it has a good current-controlled power supply with light-output feedback it should be fine.* If it has a current limiting resistor it might have a shortened life. If it relies on internal battery resistance to limit current you'll fry it, and possibly fry your power supply too.

  • Laser diodes have 3-terminals. Two are for power and the third goes to an internal photodiode to monitor light-output. In a "good" laser power supply, the light-output is monitored to keep it constant so the laser is neither over-powered or under-powered and to hold the output constant with temperature changes. It's actually the current which is being controlled and the voltage (across the laser diode) falls into place, just like with an LED.
4

DVDdoug is the closest to correct. Overvoltage will not cause a problem for what you are proposing. Green pointers, like the one you show have decent, but fairly inefficient constant current drivers and actually use IR diodes fired through a frequency doubler (doped crystal) to produce the green light. the IR diode will be a higher optical power rating than that of the pointer, and thus require more current than expected. the IR diodes have positive common (NOT negative, like other LD's). so watch power placement. Most of these type of green emitters do not have adequate (if any) IR filtering on the optical output, so, be extra careful not to point at anybody's eyes.

5

Most of these type of green emitters do not have adequate (if any) IR filtering on the optical output, so, be extra careful not to point at anybody's eyes.

Isn't laser light extremely monochromatical light? Or does light with exactly the double wavelength pass?

6

What if I run this laser with 3v for 24 hours as this one has visible beam at night and I am planning to build a laser detector for a project