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FrozenGate by Avery

Are Laserbtb 445's DPSS or Diode driven?

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Mar 31, 2014
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Hello everyone!

Just a quick question regarding Laserbtb's 445 handheld lasers. Do any of you know if they are DPSS or if they're diode driven? I have a pair of OD4 goggles that I purchased a while ago, and I'm curious as to whether or not I'll have to get a different pair that's also IR filtered. The laser I'm looking at is the PL445 - 2000, and I plan on picking it up pretty soon if IR light will not be an issue.

It does say "The blue diode portable laser,445nm,higher power." on the site, but from experience, I'm cautious when it comes to descriptions, especially when it doesn't specifically say that it is not DPSS. I bought a 532nm laser a while back that was a "diode" laser (while not technically incorrect since there is an IR diode, it is very misleading), but was in actuality a DPSS laser with no IR filter.

Is there need for such worry with Laserbtb? I emailed Kevin with my question but he hasn't answered yet. :(


Thanks in advance!


Edit: I know I can request an IR filter be installed, but my friend has had one for a while and didn't know that IR light was just as dangerous as light in the visible spectrum and didn't get one installed... So this is for his sake as much as mine!
 
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No handheld 445nm is DPSS. Might want to do some research on wavelenths prior to buying a laser
 
Haha, that's what I thought. I have done quite a bit of research, and came to the conclusion that DPSS would be too complicated for a 445, but I wanted to be safe rather than sorry.

"Blue DPSSLs use a nearly identical process, except that the 808 nm light is being converted by an Nd:YAG crystal to 946 nm light (selecting this non-principal spectral line of neodymium in the same Nd-doped crystals), which is then frequency-doubled to 473 nm by a beta barium borate (BBO) or lithium triborate (LBO) crystal."

If I understand correctly, DPSS lasers work by taking an IR diode and doubling the frequency, and by doing so, halving the wavelength, giving an output colour that is much different than that of the input colour. 532nm seems to be relatively easy to reach via this frequency doubling, whereas blue sounds complicated as hell.

Seems a bit complicated for a handheld, but I assumed that it could be feasible to have one output at 445 instead of 473nm... And while a straightforward diode seems to be the logical course of action, I'd rather be absolutely sure than just 99% sure.

Thanks for the help!
 
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Haha, that's what I thought. I have done quite a bit of research, and came to the conclusion that DPSS would be too complicated for a 445, but I wanted to be safe rather than sorry.

"Blue DPSSLs use a nearly identical process, except that the 808 nm light is being converted by an Nd:YAG crystal to 946 nm light (selecting this non-principal spectral line of neodymium in the same Nd-doped crystals), which is then frequency-doubled to 473 nm by a beta barium borate (BBO) or lithium triborate (LBO) crystal."

If I understand correctly, DPSS lasers work by taking an IR diode and doubling the frequency, and by doing so, halving the wavelength, giving an output colour that is much different than that of the input colour. 532nm seems to be relatively easy to reach via this frequency doubling, whereas blue sounds complicated as hell.

Seems a bit complicated for a handheld, but I assumed that it could be feasible to have one output at 445 instead of 473nm... And while a straightforward diode seems to be the logical course of action, I'd rather be absolutely sure than just 99% sure.

Thanks for the help!

473nm is pretty complicated indeed. If you want something even more complicated check out 593.5nm lasers. They use SFG, which combines 532nm/671nm light to produce 594nm(I think that's how it goes). Not only is it horribly inefficient, the crystals used into making the lasers are very hard to come by.
 
there is quite a difference between 473 and 445.

there are different crystals used, as well as different wavelengths of IR to start with, that produce various DPSS wavelengths.

I have not heard of a DPSS 405, 445, 450, 515, 520, 635, 650, or 660, though that's not to say they do not exist. once a diode exists in a particular wavelength, there is very little reason to get a DPSS version. indeed, I expect to see 520s replacing 532s more and more, even though the color is not exactly the same

these are pretty much always DPSS: 473, 532, 589, 594, 671. one exeption is 473, there are rare and expensive diodes at or very near this wavelength, styropyro has one. also there are other DPSS wavelengths I did not list here, but the ones I listed are the most common
 
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the prices are a clue--a non-dpss diode blue laser costs a lot less than a dpss blue of equal output power.

Good news is that 445nm diode do not output any IR
 
the prices are a clue--a non-dpss diode blue laser costs a lot less than a dpss blue of equal output power.

Good news is that 445nm diode do not output any IR

I should probably have realized that... :banghead:
 
If I understand correctly, DPSS lasers work by taking an IR diode and doubling the frequency, and by doing so, halving the wavelength, giving an output colour that is much different than that of the input colour. 532nm seems to be relatively easy to reach via this frequency doubling, whereas blue sounds complicated as hell.

Seems a bit complicated for a handheld, but I assumed that it could be feasible to have one output at 445 instead of 473nm... And while a straightforward diode seems to be the logical course of action, I'd rather be absolutely sure than just 99% sure.

Thanks for the help!

473nm , 457nm , 671nm , 589nm , 593.5nm , 532nm all start from a 808nm pump diode , The 808nm is used to pump either a Nd:YVO4 or ND:YAG crystal ( depending on the IR line needed for SHG )

This crystal will fluoresces at the intended IR line that is needed ( determined by coatings present ) and in the case of the 589nm and 593.5nm SFG systems the crystal will lase at two lines instead .

For SHG at 671nm , 473nm , 457nm , 532nm and others the IR line from the crystal undergoes the SHG where for example in a 532nm laser the IR line is 1064nm , two photons of 1064nm light are combined inside the KTP crystal to produce one 532nm photon ( half the wavelength ( shorter wavelength ) , double the energy of the IR line )

473nm is rather temperature dependant , and the gain of the IR line needed for SHG is low compared to the IR line used in 532nm systems so for a 473nm a larger pump power input is needed , requiring better thermal management , among other things .
 
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