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Help, I`ve burned my 200mW green DX module

megha

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Dear users, I`ve recently received my 200mW DX module. The negative cable (blue or black) has soldered out. When I was soldering it again, everything was ok but later it has moved and made contact with R4 resistance (the big one, light blue). The laser emited green light as usual for a very short while when this contact happened. It emits a red light from the diode (visible for the human eye) and with the camera I can see the typical violet infrared (808nm I guess) light.
Is the diode fried ? or the ktp ?

In yellow I`m showing the accidental contact that I`ve done.



I`ve another DX laser pointer 50mW (not the true 50mw one). Could I try to replace the KTP or the diode? Are the same components: 50mW (not true) laser pointer $14.99 and 200mW module $46.85 ?

The infrared does not heat, maybe the diode power has been reduced
Thanks for your help,
 
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silvercookie

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sounds like the diode shorted out. or it flared up and pooped on the KTP crystals.

dont quote me 100%.
 

StridAst

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infrared looks red, not violet. any violet color in your camera would be the camera attempting to display infrared. green lasers are pumped by an infrared diode, that is converted to green through crystals. I think the first one is changing the IR to a longer wavelength 1064nm which is still IR, but a specific color of IR, the second is doubling that 1064nm to 532nm which is green. the frequency doubler has a mirror on the front that reflects 1064nm but passes green. and a mirror on the back that passes 1064nm but reflects the green. (neither would look silver, not that type of mirror)

Ok someone correct me if I am wrong, but 1064 isn't visible to the human eye, therefore the red color you were seeing probably wasn't 1064nm. I think the diode itself is 808nm. My guess is the first crystal (the one next to the diode that converts the 808 to 1064nm) has gotten knocked loose and the 808 is shining through. Be very careful, as that 808nm would be over 1000mW (1 watt) and while appearing dim, could EASILY fry your eyes. it's much more dangerous simply because it doesn't look bright.

This is simple logic based on the concept of not being able to see easily the 1064nm, but being quite certain that you can easily see red from the 808nm. (easily being subjective here, as the red spot from a >1 watt 808nm should be easy to see) As the doubler crystal is reflecting 1064 not 808, I would assume it isn't as efficient at reflecting 808, so more would get out, it also wouldn't double 808 either, so the color would remain unchanged. I believe the crystal that is pumped to produce the 1064 is glued right in front of the 808nm diode. or should be. This make sense to anyone else?
 

megha

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I`ve changed both, KTP and DIODE. I`ve put the brass part that include diode, ktp and lenses from a 50mW Laser Pointer From DX (not the 50mW true one) and now is working.
But...
It seems that the KTP (from the 50mW) is heating too much with that driver (200mW) and the beam divides in two beams and start loosing output power fast. All that process in three seconds.
95% sure that the problem was the diode, now I`ve changed it and the problem is the KTP that seems to be 0,2mm (yes, 1/5 mm) smaller that the other one. (200mW vs 50mW)

My question is, if I found an appropiate silicon to glue the "200mW`s" KTP, would it be very hard to align ? I would take out the "50mW`s" KTP and glue the other one in the same place.

As it is, this laser is totally useless.

The other thing that I think is that the diode is doing this problem, because KTPs are almost the same size, it`s hard to see the diference. Could this be happening ?

Thanks again
 
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Scott

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Feb 6, 2010
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Hello I have accidentally put the battery in wrong in my green laser gun sight and it's nit working. Any idea what part would be damaged? (diode? Driver?). Thanks for any answers!!

Scott
 

BKarim

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it is unlikely that the 50mW diode is suited for 200mW. you can burn it!
alignement is only a problem with separated crystals and mirrors, which is not the case with composite crystals.

scott i think you have burned your diode
 
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