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Help with a laser build project

Manachan

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Hello

I have a project of making borders of lasers, so when someone cross a laser beam which is invisible an alarm is made because there is a sensor that capture the laser from the other side. For this project I decided to use TO-18 laser module because it is cheap an install it into a laser housing with collimation lens because the laser beam should travel at least 50 meters away.

After research, i have found two products from amazon:
1. Laser diode TO-18, visit the link
2. Laser housing, visit the link

My question is, is this housing have a collimation lens or no ? if no than is there an other housing for the TO-18 diode with collimation lens ?

Thank You
 
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diachi

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My question is, is this housing have a collimation lens or no ?

Thank You
Yes. Says so right in the description...

"Linse Kunststoff"

You are aware that the diode you listed can potentially exceed safe power levels for direct exposure? With an invisible laser there's the potential that someone/something could be injured. Will you be running it at 50mW?
 
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Radim

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Yes. Says so right in the description...

"Linse Kunststoff"

You are aware that the diode you listed can potentially exceed safe power levels for direct exposure? With an invisible laser there's the potential that someone/something could be injured. Will you be running it at 50mW?
I agree with what diachi said.

What about some visible laser of low power to start with? The problem with invisible lasers is they are invisible and no blink reflex protects you.

If you need working safety feature there are much better commercial solutions and perfectly safe for those disturbing protected area. You might be eventually taken to court for damaging someone's eye, so realize this risk for you.
 

Manachan

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Hello ;
Yes. Says so right in the description...

"Linse Kunststoff"
Linse Kunststoff means that it is a plastic lens, but no information if it is collimation or no. How you concluded that it is so ?

You are aware that the diode you listed can potentially exceed safe power levels for direct exposure? With an invisible laser there's the potential that someone/something could be injured. Will you be running it at 50mW?
I really don't need 50mw power at all. I think 5mw will do the job but I didn't find one with lower power and infrared as well except this one, all I found is 200 or even 500 mW. But the solution for that already exist, I am going to control the current that the diode consume using a simple LM317 circuit with a resistor. The current limiter should output around 5 mA of current multiplied by 1.5V voltage result 7.5 mW of power that the diode will consume. Also having a 50 mW diode doesn't mean it must use all its power, it is just the maximum power the diode can support before failure.
 

paul1598419

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You really should pick something besides an IR diode. It is invisible and unnecessary. The acrylic lens is the collimation lens and should work fine when focused to infinity. A red 650nm diode like the LPC-836 would be as cheap if not cheaper and would alleviate these problems. Think about it.
 

Manachan

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You really should pick something besides an IR diode. It is invisible and unnecessary. The acrylic lens is the collimation lens and should work fine when focused to infinity. A red 650nm diode like the LPC-836 would be as cheap if not cheaper and would alleviate these problems. Think about it.
At lower powers that I am working with (~ 5-8mW), even a colored red laser won't be seen even at night. I am talking about the laser beam :yh:.

Just to clarify things, the laser will be putting in a farm pointing toward a sensor which is 50~ meters farther, so I guess an altitude of 30 to 40 cm height where the laser beam will travel is very safe even for animals. Because if ever a human walk there than his or her feet/arm will cut the laser beam and then the sensor will detect it, right ?
 

paul1598419

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IR has a nasty habit of diverging faster that visible light and at 60 meters, at 8 mW probably won't work. But, it is your project and you do it the way that seems best to you. I was only trying to help out. You needn't take my advice at all.
 

lasersbee

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At lower powers that I am working with (~ 5-8mW), even a colored red laser won't be seen even at night. I am talking about the laser beam :yh:.

Just to clarify things, the laser will be putting in a farm pointing toward a sensor which is 50~ meters farther, so I guess an altitude of 30 to 40 cm height where the laser beam will travel is very safe even for animals. Because if ever a human walk there than his or her feet/arm will cut the laser beam and then the sensor will detect it, right ?
One problem that you have overlooked...
It is next to impossible to align an invisible laser on
a target 50 meter away. Been There... Done That.
You would be better off using a Red Laser. Since it
is for a farm use I don't see a need for the beam to
be clandestine.

Jerry
 

Manachan

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Okay, I will use the red one since it is cheap and easy to align also the beam is not seen at low powers. Thank you.
 




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