Sanwu pocket 405nm

[MajorLazor]

I just got one, and it looks neat so far. Two quick questions. I got it from Laser Pointer Store, and ordered a pair of safety glasses from them. They weren't very expensive, but still should be OK to use, right? There is no marking on the lens, so I don't know what wavelengths they block or the OD. They are a greenish color. Is that normal for glasses that block 405nm? I'm assuming they'd be no good for green lasers. I actually have a pair of much nice glasses by Eagle Pair, but wanted to make sure these are OK for backup.

Also, my laser came with this little part (see 2nd pic), but I'm not sure what it is....everything is in Chinese.

 

[Philipnzw]

the little thing is a USB LED flashlight, most chinese sellers throw in some random gifts into your online purchases.

 

[MajorLazor]

Ah, thanks. Nice

 

[MajorLazor]

Here's another question: should the focused beam look like this? See how there's a ring around the central dot? It almost looks like there's light leakage or something. For a 200mW laser, I'm not very impressed with the burning power, but maybe I'm expecting too much. It will eventually burn through a yellow post-it note, but it takes some time. Is this normal?

 

[MajorLazor]

Also, here's what it looks like without the lens on:

 

[MajorLazor]

Here's looking down the front of the laser with lens removed. I guess this looks normal?



Same shot, but extreme crop:

 

[DTR]

Bumper, Sorry to see that. It is common damage you see the with the blueray diodes. It has minor mirror damage in the cavity and not all the light is getting collimated properly. Some is escaping as stray uncollimated non coherent light. This light first shows as a kind of halo or giant faint ring with the raw core output in the middle. Both collapse down as you screw in the lens collimating the core. At the end you end with a beam with a flashlight focused tightly with long throw with a last beam in the middle. How pronounced this is depends on how much is leaking out.

Basically it is partially LEDed which LED is a term we use to describe the COD or Catastrophic Optical Damage. Damage to the cavity that leaves the diode electrically functional but the mirrors in the cavity are damage to the point it is unable to make the stimulate and emit as coherent light. The source light generated instead is mostly absorbing into the housing and being dumped as heat and small amounts are escaping with properties same as a LED which is non coherent

On a hopeful thought it could run like this for quite a while or just go fully LED in short order.


This can happen from shock damage maybe it was dropped at some point or it could have taken a blow during shipping. Voltage transients during switching from laser drivers that are not providing the very clean power that is required like LED drivers or other non laser driver power. Extreme heat damage can case it as well. Have seen it on NUBM/NUGM diodes that have been way overheated during extraction.

Depending on what it would take to get it fixed or fix it yourself the option of just using it till it actually goes might be the best value since it still makes a beam and burns.

 

[MajorLazor]

Thanks for this info. Yeah, something is definitely up with this laser. It'll light matches and get some things smoking, but my eBay greenie will also do that. This Sanwu just seems very weak, which makes sense, based on what you said. Since I didn't buy this direct from Sanwu, I wonder if the seller (Laser Pointer Store) will do anything to fix it. I guess I will shoot them an email and see what they say. I don't really want to go through the hassle of sending this back to China.

On the bright side, my 2W blue PL-E Mini came today from Jet Lasers. Didn't try it yet, but I'm assuming it's going to be a lot more impressive.