Hello
I need a laser diode that emits parallel / collimated laser beam.
Reason : I need to aim the laser dot at a target about 500 meters away.
What should I consider – FAC lens or collimating lens or something else ?
Thank you.
Hello
I need a laser diode that emits parallel / collimated laser beam.
Reason : I need to aim the laser dot at a target about 500 meters away.
What should I consider – FAC lens or collimating lens or something else ?
Thank you.
What size "dot" do you need at the destination?
Do you need any particular power or wavelength / colour?
- There is no such word as "can't" -
- 60% of the time it works every time -
Hello Daniel and thank you for your reply,
About my question : the dot should be round 2 to 3 mm in diameter (approx) OR square 2 mm (approx) each side.
Power :3W (I try to burn a match)
Wavelength : 980nm (I need invisible light)
I bought a 808nm diode (this number is stated by the seller) but I can see the dot - It's a weak red dot. Then I bought a 980nm diode with FAC lens. This time, I can't see the dot. I need a camera to "see" the dot but the farther I move the laser diode away from the screen the less focused the dot is
Last edited by Kwan; 07-13-2019 at 09:02.
suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.
Sorry, "Physics" says no
Diffraction will limit the minimum spot size you can focus to at a given distance. This is also wavelength dependant, so the minimum spot size is greater for an IR laser than a visible or UV for example.
Further reading:
Beam quality / Beam parameter product / M^2 of a laser
Diffraction limited beams
A very good laser might have a divergence of 1mRad for example. Most are much higher, especially multi mode diodes.
So, at a distance of 500m this would be about 0.5m in diameter
And 3W at that power density isn't going to burn anything.
- There is no such word as "can't" -
- 60% of the time it works every time -
Use a squib to do it electrically.