Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: Asellith on April 09, 2008, 08:13:26 AM
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Found This:
http://www.alliedelec.com/Search/ProductDetail.asp?SKU=387-0038&SEARCH=&MPN=OPV322&DESC=OPV322&R=387%2D0038&sid=47E84080514BE17F (http://www.alliedelec.com/Search/ProductDetail.asp?SKU=387-0038&SEARCH=&MPN=OPV322&DESC=OPV322&R=387%2D0038&sid=47E84080514BE17F)
I have read some stuff on VCSELs and I am confused on some stuff. Is this just a cheap laser diode that emits in infrared? It says the wavelength is between 830 and 865 nm and the beam divergence is 6 degrees. So can I use it to do long distance precision range finding or will the fact that it is a laser not let me easily pickup the reflected light? At $5 each if I can find a way to easily detect the light on the robots side I'd like to experiment with them.
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It looks to be a 1.5mW laser. On that same page they list some phototransistors etc that will work with it, so I would imagine you could use it as a focused range finder of sorts.
Now lets get back to the part that it is a laser, and one that is hitting on the infrared spectrum. A 5mW red laser (around 620nm spectrum) has very little IR bleed out but can still manage to cause eye damage (blind spots). The more IR a laser gives out, the more you need protective lenses to be around it when in use. Even though this is a 1.5mW laser, it is high enough in the spectrum that it would not make for a good "being around people" robotic sensor.
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Do the laser range finders use the same type of technology?
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The most dangerous laser is the green one because of eye is most sensitive to green color. IR is not so dangerous because it doesn`t focus straight on retina ( until it is not industrial CO2 "Jedi sword" of course ;D ). Another question is that laser is nearly useless in hobby robotics, perhaps only for extremely sensitive contact bumper with multimode fiber ( however, it will not be easy too because of alignment problems ). I was planning to build it, but unfortunately can`t find step-index fiber ( I have access to single mode fiber, graded-index fiber and even microstructured fiber, but not step-index one :D ). Hobby laser rangefinder is a dream.
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Im not sure what technology they use for the laser rangefinders, but I'm sure they keep it secret . . .
You definitely need additional specialized electronics to measure the range, its not like a simple emitter-detector pairing that measures intensity.