Thoughts/Insights on 532nm Laser Diode Pen (LaserBTB)

[Moultrup]

Hey LPF,

I've been looking for a slim profile green laser pen with a decent amount of power for under $100.

After lurking the forums for a couple days, I've settled on either a 520nm or 532nm. I gave LaserBTB a look through, since they've been receiving a lot of praise on here lately, which made it easy since I found this model on their page that is pretty much ideally what I'm looking for (size, color, power, price): LaserBTB's LP 515nm 532nm 1-150 (100mW for $60) shown below in the attachment. Here is a link to the manufacturer's (Osram) laser diode specification. I've been burned before after receiving a bad 1W 445nm laser from -Like, so I'm trying to do it right this time.

Anyway, I just want to get some opinions on the laser diode aspect of this pen. Some questions I have are:

• Is the divergence rating good on this laser? It's listed as <2.0 mrad, but after reading how some people got 0.25 mrad from their diodes (over 2 years ago) I'm just curious what a good rating would be today. Although, I understand that one in the link is a custom laser, so it's probably received a lot more TLC from the maker.
  
• Also, I couldn't really figure out if it burns or not. Do laser diodes differ in that field from the crystal diodes? I'm not obsessed with its burning capability but it would be pretty cool if it did.
  
• Are the heat sinks in this pen decent? I'm to understand that these don't heat up as much as the crystal diodes.
  
• Should I get an IR filter on this thing? I don't want to sacrifice power or obstruct the beam in any way unless it's almost insignificant/minor. I have goggles and it's going to be used strictly outside (mostly while camping/stargazing) and NEVER by children.

Any help/opinions would be greatly appreciated – Thanks LPF!

 

[Moultrup]

:bumpit:

 

[ChaosLord]

First thing, if the one you want is the 100mW, it will be dpss, not a diode. The diode is the top three, wavelength listed 515nm. 50mW is the strongest diode based green laser they sell.

All the ones after the first three are dpss, 532nm. So if you want more than 50mW, it will not be a diode. However, you could get a 100mW 520nm diode laser here on the forum...

As for divergence, the diode will be worse than dpss. That's about the only advantage of dpss over direct diode. In other word, if you got the 100mW, it should have very good divergence.

Yes, the 100mW one will burn if focused and is close to object. Nothing to impressive, but it can.

Heatsinking in any pen is limited, and the higher the output, the shorter the duty cycle. Laserbtb's site should list the duty cycle, but I wouldn't run a 100mW pen more than 30 seconds at most. Even that might be pushing it.

As for IR filtering, dpss needs it, and I believe laserbtb is good at filtering ir. The 515-520nm do not need it because they are diode based.

What ever get, don't forget laser safety goggles! You have to factor that into your budget.

I also suggest searching around and learn more about dpss lasers and laser diodes.

 

[mortuus]

or get their 520nm 100mw laser in the better host.