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umm this is a difficult one to anwser?
yes it was a tad brighter (the actual dot) it was slight lighter than when not running the TEC.
but i wouldnt say there was like a big noticable difference.
the diode has been running for a total of 7 hours today at 300mw. still going strong
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That's pretty well par for the course with diodes. The primary reason TECs are used as opposed to other active cooling options (which are perfectly effective if all you want to do is cool the diode) is for temperature tuning of wavelength. As you chill a diode, the wavelength gets shorter and shorter until a temperature limit is reached due to the die actually shrinking in size (contracting) from the colder temps. A properly built TEC drive circuit will allow you to set the TECs temperature precisely, which is a large contrast from fans which cool very well, but not precisely at all. Using this concept, it becomes possible to match a pump diode's wavelength directly to the crystal's peak absorption band. This greatly improves efficiency. Then, if you're using a nonlinear crystal (frequency doubler), you can add another TEC for this. In green systems KTP actually becomes more efficient at it gets warmer until a peak efficiency is reached. In this case it is often helpful to use the TEC in reverse so that it warms that crystal rather than cool it. In blue systems the LBO has a very narrow temperature curve and it will not function at all outside of this curve. Therefore, with LBO, temperature tuning is required to get any doubled output.
These techniques allow for lasers using them to be tuned for maxmum output without ever touching the pump diode current. In some cases quite a few extra mW of output can be gleaned simply by taking some time and tuning carefully.
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ok got bored of 300mw so turned it up to 350mw. when the diode was running at 300mw is hopped around between 2 mw's.
when it was running at 350mw it hopped around between 10mw's, it was constantly changing -dropping and then going back up.
diode ran fine for 4 hours at 350mw then went pop.
so the out come of this thread is the diode should run for many many hours at 300mw and it does not need to be mega chilled.
just some simple temp control
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Nice experiment, thanks
Was it a diode extracted from a LPC-815? You said that was a 16x writer diode, but I'm not sure about the LPC...
The next one is to find the lifetime of a diode with a pulsed use, at a duty cycle typical from a laser show use, it should be even higher
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Nice test, it would probably have lasted a bit longer in a projector, being blanked, but nice to know that tree fiddy is pushing them a bit too far.
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using a heatsink with a fan should work.. z-bolt style heatsinks work awesome. I have a lifetime test in progress using a long-die open can diode in a z-bolt heatsink with a fan. The diode is set to ~300mW also and has been running for about 1500 hours so far..Originally Posted by andy_con
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nice .using a heatsink with a fan should work.. z-bolt style heatsinks work awesome. I have a lifetime test in progress using a long-die open can diode in a z-bolt heatsink with a fan. The diode is set to ~300mW also and has been running for about 1500 hours so far..
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And what about your diode type?Nice experiment, thanks
Was it a diode extracted from a LPC-815? You said that was a 16x writer diode, but I'm not sure about the LPC...
The next one is to find the lifetime of a diode with a pulsed use, at a duty cycle typical from a laser show use, it should be even higher
Senior Member
yes one of them sleds.Nice experiment, thanks
Was it a diode extracted from a LPC-815? You said that was a 16x writer diode, but I'm not sure about the LPC...
The next one is to find the lifetime of a diode with a pulsed use, at a duty cycle typical from a laser show use, it should be even higher
i think a fair test would be to just set it at 300mw with the tec running and see how long it lasts.
the diode did get a bit of a workout.
had the diode not been treated so badly i suspected it would have lasted alot longerNice test, it would probably have lasted a bit longer in a projector, being blanked, but nice to know that tree fiddy is pushing them a bit too far.
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My only worry about my test is the fact that all diodes vary considerably in life expectancy when they are run above their maxmum ratings. Some people might have great luck, while someone else might have no luck. The ideal method for determining lifetime would be to run several tests simultaneously and average the results.
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