B&W Tek BWB-10-OEM - 473nm 10mW

styropyro said:

It better be fun considering I have 9 of these bad boys to tinker with.

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So you were the one that bought them all?
But maybe I should thank you, They shipped me 2 low power units instead of broken unit because they ran out of those...

Before this seller appeared I bought a B&W tek module that was supposed to work but ran in TEM02. I managed to fix it though, so I have good hopes of fixing the next two.

I was just hoping for one to tinker with seeing as they were so cheap. But I guess I'll just wait until next time.

I didn't buy them all, there are still 8 left. eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

The broken ones are usually easy to fix from what I've read.

Everytime they sell put they Usually put more up. Those b&ws have been on there for awhile

I just wonder what these are out of, since judging by the auctions with the spectro heads.. The spectrometers they sell are apparently out of the same piece of equipment as well.

Didn't it or somebody somewhere say they came from medical equipment? I wonder what would require a spectrometer also? Maybe to make sure the lasers were running at 473nms...

No Whatever they came out of measured fluorescence. The 473 just illuminated whatever the target material was.

I'll carry mine home and take some pics of the whole setup this afternoon.

Just got one of the "working" units in the mail today. Out of the box with no modifications, it outputs 6mW of clean TEM00. I almost don't want to mess with it because it's so nice so far.

Edit: Just took off the feedback sensor and I'm getting a very stable 25mW. Do I dare mess with the pots?

They come from American biosciences gene sequencers and scanning confocal microscopes. They have been replaced by direct diode lasers. They sell on ebay for a small fraction of their new cost.

styropyro said:

Just got one of the "working" units in the mail today. Out of the box with no modifications, it outputs 6mW of clean TEM00. I almost don't want to mess with it because it's so nice so far.

Edit: Just took off the feedback sensor and I'm getting a very stable 25mW. Do I dare mess with the pots?

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If you pull the feedback off, the pots become useless.. Its a one or the other situation
for these lasers.

Playing with the alignment can get you some decent power from those. If there is
no mode issues from the get go, you shouldnt encounter any..

Just remember when re-aligning start from the first optic in front of the pump and
work your way forward to the the crystals. Moving the crystals alone wont do much.

Thanks for the info, that's just what I was looking for as I am hoping to try my luck with crystal alignment.

If you need any help, let me know, I went through 30 of them keeping the ones
with a successful re-alignments.

Also watch when you take it apart, the TEC platforms are shimmed as well as the optics
in some. You don't want to lose any of the small pieces..

On average I spent a few hours on each one. Some could not be improved but
some improved big, as in 90mW big

You also have 808 and 1064 that can stray, be sure to use good goggles..

90mW from one of these is insane, hopefully I'll get lucky with a few of them. I'm still having fun with my 25mW labby I just got, even though I could be playing with my nearly 300mW 473nm Lasever module...I think knowing I got something for cheap makes me enjoy it more.

What are you using for eye protection? I have some high-OD 808nm goggles but I don't have anything for 1064nm.

Mind you it was only one unit that hit 90mW but had others ranging from 30mW, 50mW,
55mW etc etc..

Without the feedback, I have measured 800mA to the pump diode at most, so without
it the only problem becomes heat. Both on the driver and the laser head itself. The head
will get warm after 30-45mins.. A easy solution is a small fan for the driver board, and
one for the head. The output drops a bit once these get too warm..

I got my goggles some time back, they are rated for both IR wavelengths. A lesser
OD rating for the 1064, but there is more 808 anyway, so that's no biggie. A simple
test with an IR sensitive cam can be performed by opening one of the heads and
placing the goggles in front of your cam. If you don't see any light, you should be okay.
The exposure to the 1064 is minimal unless you are using a mirror.. The beam passes
straight through to the front of the laser, and the only reflections would be straight
back off the copper mount for the LBO, or your finger tips..

You may also want to be careful with the TEC's in those, they are quite fragile.
I have seen the TEC for the crystal set broken several times vs the pump LD's
TEC which I saw once or twice. In all cases the TEC had split into 2 pieces.
These are good units that ended up selling as 'bad' for obvious reasons,
but tend to be nice for output when the bad TEC is replaced.. :san:

A broken TEC not only fails to maintain the set temperature, but it kills the
alignment between the 808 optics and the crystals..

I got my shipment of the non-functioning lasers yesterday and I got to start playing around with alignment. I started with the laser that was the "most" broken so if I messed it up, it wouldn't matter too much. Without really knowing what I was doing, I got that module to output 35mW-45mW, but the beam quality is still useless so far.

styropyro said:

I got my shipment of the non-functioning lasers yesterday and I got to start playing around with alignment. I started with the laser that was the "most" broken so if I messed it up, it wouldn't matter too much. Without really knowing what I was doing, I got that module to output 35mW-45mW, but the beam quality is still useless so far.

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Did you find a small piece of chinese soda can in there?? lol I have found that
CNI likes this method to correct the output..

If the mode is really bad, try flipping around the LBO crystal.. This sometimes will
correct the issue, but I wouldnt expect a perfect beam.

45mW is a great start, and a good practice run to get the feel for things.
Just watch, one wrong move and your back to square one with little output.
I had one that hit 50mW or so, looked at it 'the wrong way' and the output fell wasting
a couple of hours work