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Question About Duty Cycle

LesPaul

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Jan 27, 2012
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Hey,
I have a question regarding duty cycle:

What makes the duty cycle higher? Is it the host the module is in, the module or what?

If I were to put a 100mW green laser module in a pen host, what would the duty cycle be like? What if I put it in a Aurora C6?

Thanks!
 

Seoul_lasers

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Not as black and white as simply putting it into a heatsink.
In the case of a diode laser, generally the larger the host (taken into consideration, host material, and type of construction) generally means longer run time. However this being said, the operational current of the diode needs to be taken into consideration as well.
On a green laser, there is a much more complicated process taking place. There are 2 crystals being pumped by IR light from a 808nm diode. Green DPSS lasers need lots of cooling, and therefore the better(thicker) the host the better performance. DPSS lasers are also temperature dependant. Too cold and the laser fails to lase, too warm and you can either fail to lase or in an extreme case fracture your crystals (extreme heat). So, this being said DPSS lasers need a specific temperature range to operate in.
Small pen DPSS lasers aren't ment to run more than 20-30secs... DPSS lasers in larger wand hosts can run for up to several minutes.


Anyone else to chime in?
 
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LesPaul

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Thanks for your answer, it's exactly what I needed. +1

Not as black and white as simply putting it into a heatsink.
In the case of a diode laser, generally the larger the host (taken into consideration, host material, and type of construction) generally means longer run time. However this being said, the operational current of the diode needs to be taken into consideration as well.
On a green laser, there is a much more complicated process taking place. There are 2 crystals being pumped by IR light from a 808nm diode. Green DPSS lasers need lots of cooling, and therefore the better(thicker) the host the better performance. DPSS lasers are also temperature dependant. Too cold and the laser fails to lase, too warm and you can either fail to lase or in an extreme case fracture your crystals (extreme heat). So, this being said DPSS lasers need a specific temperature range to operate in.
Small pen DPSS lasers aren't ment to run more than 20-30secs... DPSS lasers in larger wand hosts can run for up to several minutes.


Anyone else to chime in?
 

tsteele93

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Dec 27, 2011
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Not as black and white as simply putting it into a heatsink.
In the case of a diode laser, generally the larger the host (taken into consideration, host material, and type of construction) generally means longer run time. However this being said, the operational current of the diode needs to be taken into consideration as well.
On a green laser, there is a much more complicated process taking place. There are 2 crystals being pumped by IR light from a 808nm diode. Green DPSS lasers need lots of cooling, and therefore the better(thicker) the host the better performance. DPSS lasers are also temperature dependant. Too cold and the laser fails to lase, too warm and you can either fail to lase or in an extreme case fracture your crystals (extreme heat). So, this being said DPSS lasers need a specific temperature range to operate in.
Small pen DPSS lasers aren't ment to run more than 20-30secs... DPSS lasers in larger wand hosts can run for up to several minutes.


Anyone else to chime in?
I have an RPL-165 from optotronics that has a duty cycle of "until the battery runs down" but I believe they are using a thermo sensor that reduces power when it starts to get hot and it is an enormous heat sink anyway.

"How long can my RPL laser run before it needs to cool off i.e. duty cycle?

The adjustable RPL has the ability to tune the amount of IR diode current so that the optimum amount of IR goes to the crystal. If more than the optimum amount of IR hits the crystal, the crystal becomes over saturated and 532nm output no longer increases. Only more heat is produced and in fact this can cause output to decrease some. When the RPL laser is tested, the optimum current level setting is noted in the customer documentation and this is the same current level that the average output power tested and recorded for the customer. Most of the time, this current level is #4 or #5 and adjustable RPLs sold after 2/1/2007 will run until the battery dies at this level (no duty cycle). The reason we give a recommended duty cycle of 5 minutes on and two minutes off is that some users will buy the non-adjustable model and it's current cannot be tuned. It is safe to leave the RPL on until it shuts itself off, in fact that is what the battery protection circuit is for. The shut off is to protect the battery from excess discharge/low voltage as this can be dangerous for lithium-ion cells. The RPL diode is never ran at more than 80% of it's rated operating current, so as long as the ambient room temperature in the spec does not exceed 30C, the diode will be not be thermally damaged by extended use."
 
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