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[Request] List of wavelengths that are created from dpss lasers

Anonymous0531

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Sorry for so many posts asking for stuff. I'm just new to this and don't know much about it, and I want to do it safely.
 



paul1598419

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Are you kidding me? That is a very long list. Try searching for all DPSS laser wavelengths. Just in yellow, and off the top of my head, these include 565nm, 575nm 577nm, 589nm, 593.5nm, etc.
 

ZRaffleticket

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I have a theoretical chart linked in my sig if you want to go real crazy with it...

 

ZRaffleticket

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It can be done... But there's almost no reason not to use a diode for that wavelength unless you're doing some real finicky science. Since that's usually associated with the blue component in display technology diodes are probably the answer to every problem anymore.

Also look at 488nm. You can get this wavelength with just about every laser process. Argon gas, dpss, opsl, fiber, diode, etc. Each has their own set of advantages and disadvantages depending on the application.

A good rule of thumb, if the wavelength ends in 0 or 5, it's likely a diode. Ex 405, 445, 450, 465, 505, 520, 635, 650. Then you have odd cases like 488 which will often be listed as 490.
 

thebouljello

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It can be done... But there's almost no reason not to use a diode for that wavelength unless you're doing some real finicky science. Since that's usually associated with the blue component in display technology diodes are probably the answer to every problem anymore.

Also look at 488nm. You can get this wavelength with just about every laser process. Argon gas, dpss, opsl, fiber, diode, etc. Each has their own set of advantages and disadvantages depending on the application.

A good rule of thumb, if the wavelength ends in 0 or 5, it's likely a diode. Ex 405, 445, 450, 465, 505, 520, 635, 650. Then you have odd cases like 488 which will often be listed as 490.
Why do diode laser wavelengths usually end in 5? Does that have to do with the semiconductor material?
 

ZRaffleticket

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No - the reason is diode wavelengths aren't going to be as precise in most situations. Manufacturing differences can make two diodes in the same batch noticeably different wavelengths, so usually an average wavelength is what is advertised. Then in the specs they state something like +/-5nm to account for the differences you may get.

Typically they round off the number to make it more human readable, going by 5s is just usually what ends up happening in a product listing. No reason other than having a pretty number.
 

thebouljello

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No - the reason is diode wavelengths aren't going to be as precise in most situations. Manufacturing differences can make two diodes in the same batch noticeably different wavelengths, so usually an average wavelength is what is advertised. Then in the specs they state something like +/-5nm to account for the differences you may get.

Typically they round off the number to make it more human readable, going by 5s is just usually what ends up happening in a product listing. No reason other than having a pretty number.
Ah interesting. Is there any reason why the advertised wavelengths for DPSS lasers are more accurate? This is interesting. I never noticed how diode lasers are always in increments of 5 because of the batch error.
 

paul1598419

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Ah interesting. Is there any reason why the advertised wavelengths for DPSS lasers are more accurate? This is interesting. I never noticed how diode lasers are always in increments of 5 because of the batch error.
Yes, It has to do with the Neodymium expulsion wavelength as being ~1064nm. Double the frequency of that to 532nm and there you are. The most frequently used doubling crystal is potassium titanyl phosphate, or KTP.
 
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ZRaffleticket

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Yeah. DPSS technology often has more precision because the crystals involved fundamentally can only emit certain wavelengths of light. There's still a small range to it, but truly not much. Diode 808nm +/-5 -> Nd:YAG -> 1064nm -> KTP -> 532nm

Plus the doubling itself cuts down the margin of error. For example it is possible to directly double a diode. If the diode is 1000nm +/- 5nm you'd see 995nm-1005nm. Double the frequency (meaning the length between the waves is halved) and you see 497.5nm-502.5nm --- 500nm +/-2.5nm.
 

thebouljello

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Interesting. I am familiar with the wavelengths changing by a factor of 2 in DPSS lasers. Thanks for the explanation.
 




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