Blue Laser - Visible Beam help!

sonnyangell

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Feb 23, 2017
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Hello!

I am looking for a solution to my issue with a blue laser diode, I had purchased one on amazon that is 405nm 3V/5V 20mW. I need to have a constant beam to be emitted from this diode for an ON-stage lighting effect, as a test..originally I had this working with 2 simple AAA batteries, and it worked perfectly.


https://www.amazon.com/dp/B014WZV9DA/?tag=cpf0b6-20


However after trying again with a new laser diode of the same output, the beam dims after a second or two.. I will shut off the laser and try again with the same outcome. I need a constant beam that can be seen without smoke. Could you offer some advice on this?


Thank you!


-Sonny
 

FRITZHID

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Jun 20, 2011
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Icelandic wastelands of Monico, WI
sounds like you're overdriving the laser diode. most need a constant current driver to limit current to prevent overheating and damage. not all laser diodes are rated the same input to equil output wattage.
 

sonnyangell

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Feb 23, 2017
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Yeah, that's what I figured as well. Im pretty sure the diode is rated for 3.7V so I purchased a 18650 (3.7V) battery Hoping that might do the trick..


I used a CR2032 (3V) battery as a test and it was dim - then I used 2 and I could see the beam for about a second then it dims - then I put in a resistor to put it about 3.2 and it was dim right away (after that i took out the resistor and it was bright beam again, then to dim) so the diode should not be damaged...I dont think

But technically if I hook up the 3.7 battery to this diode it should just have a nice constant beam right? I don't need anything else?
 

FRITZHID

Flashlight Enthusiast
Joined
Jun 20, 2011
Messages
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Location
Icelandic wastelands of Monico, WI
Yeah, that's what I figured as well. Im pretty sure the diode is rated for 3.7V so I purchased a 18650 (3.7V) battery Hoping that might do the trick..


I used a CR2032 (3V) battery as a test and it was dim - then I used 2 and I could see the beam for about a second then it dims - then I put in a resistor to put it about 3.2 and it was dim right away (after that i took out the resistor and it was bright beam again, then to dim) so the diode should not be damaged...I dont think

But technically if I hook up the 3.7 battery to this diode it should just have a nice constant beam right? I don't need anything else?

if you connect an 18650 to the laser diode without a driver, you will no longer have a laser diode. it might glow for a sec to a min or so but it WILL fry in short order if not right away. you need to find the proper driver for that LD to limit the current properly.
 
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