Hello from Massachusets!!!

[GSS]

thanks but I’m not looking for a yard security beam like you linked. Also this system would not be unattended like you say. As I described in OP, it’s for novelty/show piece. I understand the risks.
I also tested a cheap 5mw green ebbay laser and it shows a pretty good beam at night outside so not sure why you said it should be over 5mw.

Just trying to get some advice on how to build this, not sure why some of you who responded seem to be so uptight here.

Just to know that those cheap ebay pointers are very under rated so they can sell them. They can be anywhere from 40mw to 80mw.
Just telling you so you can be careful.

 

[Oray111]

Ok I see. I didn’t know it could be falsely mislabeled for its power if it’s from eBay.
I bought a 5mw green laser diode and power supply from a legit laser company so I can compare and test to the eBay one.
Will come back when I test it Thursday.

 

[RedCowboy]

Ok I see. I didn’t know it could be falsely mislabeled for its power if it’s from eBay.
I bought a 5mw green laser diode and power supply from a legit laser company so I can compare and test to the eBay one.
Will come back when I test it Thursday.

#1 You are responsible for any damage/loss resulting from any unsafe laser device you build/use, I am only discussing the scientific/academic aspects. Remember that any laser over 5mw can cause permanent vision loss.

The beam will look brightest when you are in line with it, but from the side the beam of a true 5mw green laser will disappear pretty quickly with any distance depending on atmospheric conditions, ect.....

Yes ebay 532nm pointers labeled 5mw are typically 40-80mw so be aware and the only way to know the output is to test it with a Laser power Meter ( LPM )

Is this video helpful ? You can also make your own, all the information is online.

 

[Oray111]

#1 You are responsible for any damage/loss resulting from any unsafe laser device you build/use, I am only discussing the scientific/academic aspects. Remember that any laser over 5mw can cause permanent vision loss.

The beam will look brightest when you are in line with it, but from the side the beam of a true 5mw green laser will disappear pretty quickly with any distance depending on atmospheric conditions, ect.....

Yes ebay 532nm pointers labeled 5mw are typically 40-80mw so be aware and the only way to know the output is to test it with a Laser power Meter ( LPM )

Is this video helpful ? You can also make your own, all the information is online.

Thank you! That’s exactly what I’ve been looking for. A system that would receive the beam and turn on a light or alarm when the beam is broken.

Much appreciated