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Who has the Oldest Green Laser?

murrat

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This is the collimating lens under the cap
 

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murrat

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This is IR filter under the collimation lens
 

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murrat

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The laser driver and diode cyrstals and diverging lens are at the left part, the middle part consist of IR filter and collimation lens and the last part is the cap.
 

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murrat

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You can see KTP cyrstal under diverging lens
 

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murrat

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Here you can see diverging lens better.
 

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Benm

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I suppose its a difficult question no matter how you look at it, even if its just pointers.

Oldest can mean the first construction date, but perhaps also with the most runtime on it. As pointed out in the opening post, getting close to the thousands of hours specified is difficult for a pointer, and would take a decade of 1 hour a day use.

I suppose it would be feasible to just test it though - get a couple of pointers, hook them all to a 3.0 V power supply and see how they fare. Quoted lifetime would be reached in a year or so, and we can see which ones die.

Problem is: is such a test fair? Wouldn't the button be the component to fail in real world use? You get a similar thing with TL lighting: some tubes last 5000 hours under real use, but make it to 20.000+ in single-start applications. You have to be very specific about conditions.

As for the oldest greeny: i suggest sticking to the first constructed that still works, regardless of how much it has been used. It's not a fair comparison, but gives us nice pics of lasers from ancient history, and thousands of dollars spent on a milliwatt ;p
 

murrat

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I've got my answer :)

They don't really die by time. They die because of wrong use (getting to hot to fry the diode) or being unlucky like me (power loss with no specific reason) :)

I wish I could understand the reason so can decide I can fix it or not :)
This is really disturbing to see your 100mW laser you were using yesterday, behaving like a 30mW laser when you wake up in the morning :(

I'll build my own when I buy a green diode from o-like. So I'll be sure to have a better heatsink even I'am sure I haven't harm mine because of everheating. :cool:
 
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Somtimes they die because they have had there time it is time for them to go to a better place, laser heaven...
 
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murrat said:
I've got my answer :)

[highlight]They don't really die by time[/highlight]. They die because of wrong use (getting to hot to fry the diode) or being unlucky like me (power loss with no specific reason) :)

[highlight]I wish I could understand the reason so can decide I can fix it or not :)[/highlight]
This is really disturbing to see your 100mW laser you were using yesterday, behaving like a 30mW laser when you wake up in the morning  :(

I'll build my own when I buy a green diode from o-like. So I'll be sure to have a better heatsink even I'am sure I haven't harm mine because of everheating. :cool:

I mentioned the reason in my last post.. All lasers gradually fade if they don't just die first. Eventually your laser will die completely too.. :'( The only way for you to repair that laser is to replace the pump diode. There are no other user-repairable parts in there..

All lasers are very much affected by time in terms of the amount of hours they are used, and with gas lasers even just letting them sit without using them can cause them to require a gas recharge.
 
It is cool to see how the technology has changed, as well as the prices. What we routinely pay US$20-50 for today cost many hundreds just 15 years ago.. Even 5 years ago they were much more expensive than now. But that's just the way of things. 25 years ago an entry level computer cost $4000 or more. Today you can easily find one for US$250-300 for a basic system..




500
 
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usakicksass..........in your photo there is an rpl ....450mw..... does it exist???? i know that the 425 is a new addiction how could you have a labeled 450mw???
 
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Murrat:
The decrease in power output may not be because excessive voltage.
I've given my X105 up to 4V and it still burns.

Maybe I just got lucky.

Have you tried cleaning the battery contacts?
 

murrat

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ElektroFreak said:
If your laser is fading it is either because of pump diode facet damage or crystal misalignment/grey tracking.. (of course this is assuming you're using fresh batteries).

EllectroFreak, how pump diode facet damage or cyrstal misalignment/grey tracking(What grey tracking means?) can happen as all are enclosed in a small diode module? If the problem is pump diode it can be fixed otherwise not as I understoon from your post. It sound better to build my own green laser :cool:

RA_pierce, I agree with you I don't think the excessive voltage was the reason too. I'll check the battery contacts.

I will go on using it and will inform all if it get its power back again (I hope ;) )
 
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That's a really good question. The facet damage happens gradually over time due to photons impacting the facet's mirrored surfaces. How long this takes depends on the quality of the diode itself, most diodes in Chinese greens aren't the greatest quality and can show signs of facet damage quite young. This damage can be accelerated by overvoltage/overcurrent. These factors (quality, current, voltage) determine the mean time to failure (MTTF) of the laser. As long as you obey the published specifications for the laser diode in question, then they should last around 5000-10000 hours. This means that facet damage still occurs even at the recommended operating specifications, it just takes a long time for the damage to be noticeable.

Grey tracking occurs inside the crystal set of DPSS lasers. Some crystals form a grey area inside them due to lengthy exposure to excessive pump power, which impairs their perfomance. With today's crystals, this is quite rare since they are generally of fairly high quality. Most likely the problem is with your diode.

In the case of laser pointers, the fact that they are repeatedly turned on and off frequently throughout their lives also shortens their life expectancy. None of the cheap driver circuits that are attached to green pointers are absolutely perfect in their regulation, and so every time you hit the switch, tiny current spikes are fed to the diode. While they are certainly not enough to kill the diode by themselves, they do help to shorten the lifetime.

The published lifetime estimates of lasers are only a rough estimate. Depending on conditions, they can last anywhere between a couple milliseconds to 50,000 hours.

In your laser the only replaceable part is the pump diode, yes. You can't replace the crystals without much more trouble than you want, trust me.
 

murrat

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Is that all means that if something was wrong with the cyrstals no green will show up.
The problem is most likely the diode.
And trying to change the diode is nonsense as you can buy a green diode module instead ;)
Thanks for explanation :cool:
 




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