Green Laser Pointer With Ir Filter

Daniel rivera 2 337 views.

Green laser pointer with ir filter.

Importance of an infrared filter in a green laser pointer. This is already broken green laser. I use a cheap allegedly less than 5mw green laser pointer to point things out in the night sky at public astronomy events. Unfortunately recent nist tests show that a lot of green laser pointers generate a lot of extra visible and infrared light.

Make sure to only purchase green laser pointers with ir laser. You can see below in visible light the green emission of the laser is completely blocked by the infrared filter. It has a very narrow band filter 25 nanometers that is claimed to eliminate 99 of 532 nanometer laser light. Today you can buy a green laser pointer the size of a ball point pen for 15.

When opening the laser i found that there is no ir filter installed. Because of the narrow bandpass they do not adversely degrade color recognition. In cheaper green lasers and most pointer style green lasers this infrared filter is very weak or completely omitted so the laser actually emits both green and infrared light at the same time. Using camera in night mode i noticed that its shining a lot of ir which is invisible to eye.

The absence of an ir filter is usually to save cost at the expense of operator safety. Humans can incur significant eye damage by exposure to invisible light before they become aware of it. Some cheap green lasers can emit up to 10 times the green light in invisible ir infrared. The sperian laser gard model we examined is for nighttime protection against the most common green laser pointers.

Click on the image for a larger view. The infrared one can do something about. Coatings and a filter allow only the green light to exit the device. Cross section of a typical green light laser pointer.

300mw red laser pointer pop balloon duration. An infrared beam 808 nm passes through a neodymium doped crystal which converts the energy to green light 532 nm and longer wavelength infrared light 1064 nm. All green laser pointers sold by laserglow have a quality ir filter installed and as a result there is no ir leakage from the laser diode.