Laser Receiver Module

[moh17]

I'm planing to create a proximity sensor range 1m using a laser receiver module specifically for 405 nm wave length. I received the module and I need help to find a true less than 5mw 405 nm laser module, since having direct eye exposure is very very possible. I was thinking using IR laser instead, since IR receivers are less expensive however, there is no blink reflex with IR lasers, thus, they are very danger even at 5 mw.

 

[Pi R Squared]

I am not sure I would consider 5mW of 405nm eye safe or not, I wouldn't want it shined in my eye. You might try one of the ones sold here: http://www.aixiz.com/store/index.php/cPath/54
Any chance you could use a 650nm red instead? If so you could get a 1mW module: http://www.aixiz.com/store/index.php/cPath/59

Alan

 

[moh17]

I am not sure I would consider 5mW of 405nm eye safe or not, I wouldn't want it shined in my eye. You might try one of the ones sold here: http://www.aixiz.com/store/index.php/cPath/54
Any chance you could use a 650nm red instead? If so you could get a 1mW module: http://www.aixiz.com/store/index.php/cPath/59

Alan

Thanks, only wave length from 400 nm to 450 nm the sensor can detect. I want be different and use a violet laser, 5 mw is relatively safe. I can't relay on Chinese onc. You buy it as less than 5mw and have a class 3b laser. Is this one a good choice or the mini one ?. Thanks a lot

http://www.aixiz.com/store/product_info.php/cPath/54/products_id/372

 

[Pi R Squared]

I would trust the mini one more to be 5mW or less but it's not for certain. One thing you could do is try to run it at a slightly lower voltage if it will still lase, then it may have less power.

Alan

 

[moh17]

I would trust the mini one more to be 5mW or less but it's not for certain. One thing you could do is try to run it at a slightly lower voltage if it will still lase, then it may have less power.

Alan

Thanks, I bought the mini one, I will connect it to a potentiometer to play with the current or I may power the laser directly from a micro controller pin which is a low amp pin, thanks

 

[Eudaimonium]

I was thinking using IR laser instead, since IR receivers are less expensive however, there is no blink reflex with IR lasers, thus, they are very danger even at 5 mw.

Actually that's wrong, according to Wiki article:

Laser safety - Wikipedia, the free encyclopedia

The near-infrared and IR lasers within 800nm or so range can only ever cause thermal damage. Visible lasers also damage the light receptors themselves, so even if there's no thermal damage they're still dangerous, BUT, with IR lasers that produce no such effect, and no thermal effect at lower powers such as 5mW, they're actually safer than visible lasers in that context.

 

[moh17]

Actually that's wrong, according to Wiki article:

Laser safety - Wikipedia, the free encyclopedia

The near-infrared and IR lasers within 800nm or so range can only ever cause thermal damage. Visible lasers also damage the light receptors themselves, so even if there's no thermal damage they're still dangerous, BUT, with IR lasers that produce no such effect, and no thermal effect at lower powers such as 5mW, they're actually safer than visible lasers in that context.

You are right but I can't guarantee the IR laser to be 5 mw or less, neither I gurantee the 405 nm laser to be less than 5mw accuratly. I had a direct eye exposure with a 20 mw blue laser for less than a second while I was shining the laser around my room. I thought it is less than 5 mw as labeled without the blink reflex and luck , I might have had permanent damage which didn't occurre and was confirmed by an optometrist.

 

[Eudaimonium]

You are right but I can't guarantee the IR laser to be 5 mw or less, neither I gurantee the 405 nm laser to be less than 5mw accuratly. I had a direct eye exposure with a 20 mw blue laser for less than a second while I was shining the laser around my room. I thought it is less than 5 mw as labeled without the blink reflex and luck , I might have had permanent damage which didn't occurre and was confirmed by an optometrist.

If that's the case, I'd recommend going with visible laser, simply seeing where the beam is going adds additional layer of security to the whole setup.

 

[Hiemal]

Well, you could just buy a 5 mW 405 nm diode and make a driver that runs it at a much lower power, at like 1 mW (or lower, like just at lasing threshold). Anything lower than 1 mW should be eye safe, I think.

You'll have to get some pretty precise current output, though, but it could definitely be done.

 

[moh17]

Well, you could just buy a 5 mW 405 nm diode and make a driver that runs it at a much lower power, at like 1 mW (or lower, like just at lasing threshold). Anything lower than 1 mW should be eye safe, I think.

You'll have to get some pretty precise current output, though, but it could definitely be done.

I do not think there is a true 405 nm diode. I checked the data sheet of most of the diode manufacturers. I found 6 companies that manufacture the diode. For example, Panasonic have the most lower mw at 10 mw, other company have 12 mw, and Sony have 20 mw diodes which is probably used in play station 3 and 4 and most Sony readers. I'm not sure if there is a true 5mw diode but even 10 mw can be reduced to 5 mw. I'm not sure if a 20 mw diode can run on 5 mw or not but off course it can run on much lower mw than the 20 mw.