473nm Wonderland

[bloompyle]

Hello friends

So, recently you may have noticed me at 3999 posts, or, for a brief moment, at 4000. I then had to frantically find, and delete an unimportant post.

HOWEVER!!

The time has come to finally post my 4000th post and LEAVE it

SO HAPPY 4000!!!

I come to you with 3 473nm heads that were previously working, but missing quite a lot of power to their "punch".

For a long time I had a B&W Tek doing some borderline "New Wish pen" quality output. We'll get to that last ...

A couple weeks ago, however, I received an interesting email from Sam during a conversation regarding my interest in DPSS experimentation.

I have a sick blue DPSS laser, cheap Chinese import that is supposed
to be 200 mW but is more like a few mW with a crappy beam. I believe the
problem to be in the crystal assembly, which unfortunately is rather small and
may be difficult to really repair. But you're welcome to one of these for
next to nothing. The pump diode is probably good and would produce 3 W
or more with FAC. If nothing else, you could use it as a pump for your
other crystals. The driver has current and TEC trim-pots (1 TEC). If
you're serious about DPSS, might as well clear out my junk and give it
to you as long as you promise not to take out your remaining good eye
with the pump beam. ;-)

It later sweetened to a 2 for 0 deal, with 2 heads + 2 PSUs.

I am sending 2 DPSS laser heads with power supplies and cables.

One laser used to produce over 100 mW (with crappy beam) but now does only
25 or 30 mW. Possibly its TEC finally came loose just sitting. I believe
the PSU with the round key had been adjusted for this head, but either
will drive it with a similar power now.

The other one had a broken TEC which has been removed. I included a
replacement which is the same size and may be compatible. I thas the
same number of junctions but I can't tell if it is identical.

Even if you can't get the lasers to do decent power, the pump diodes, TECs,
and power supplies should still be useful. They are just sitting here.

So, now the fun begins!!

Fortunately, and unfortunately for the same reason, these didn't need any actual alignment of the crystals to get some nice output. Though I have yet to tinker, once I have both re-epoxied and ready to go, and tested, I will realign the worst of the two.

So that leaves me with 1 B&W Tek doing nothing, one MG 473 doing nothing, and one MG 473 doing some very spotty output.

LET THE GAMES BEGIN!!!

So I got to work on the first one. I soldered on a fresh new TEC, and epoxied it all back together. And weighed it down overnight. Notice the "every guy science" happening here.

The next morning, we had our first photons from this bad boy

The second MG head is currently on hold. There is a lot of extra buildup of dried epoxy where I need to put the TEC. Too much epoxy tends to have the OPPOSITE effect of having a small amount. So now I am in the need of some sandpaper to remove the excess dried epoxy. So it is now in this state ...

Here we have the heatsink that holds the diode and crystal assembly. The large chunk of aluminum you saw in the previous image was the massive heatsink for this badboy. It also just so happens to be fan cooled.

However, this is just the diode and crystal assembly, with the loose TEC (white square) hanging next to it.

Here's just another shot of the assembly.

Also ... last but not least, we have the B&W Tek that I got into today. I remembered that I bought some IR/DPSS rated laser goggles so I can REALLY play with this stuff. Though when I dug a bit deeper, I saw that one of the wires, and a couple of the TEC's teeth, had been broken off. So it's basically useless for now.

Until I can replace this TEC, it will be in the state it is in now ... have respect for the dirty desk ...

When I removed the LBO/BBO (not sure which this is) I noticed that each end looked VERY scratched. Thoughts?

So in closing, it's been a fun ride so far getting these to where they are now. I currently have one in tip-top shape, and one other not far behind. Then there's the B&W ... This will be the real test for me, and I look forward to ever minute of it

For your viewing pleasure, I took some shots of the healthy MG unit, so take a moment to enjoy some beautiful 473nm goodness

Take care friends

 

[crazyspaz]

4,000 posts, wow! Congrats I sure am jealous of all that you get to work on...I keep meaning to snag a B&W head off ebay, but there havent been any in a while it seems. (Side note: anyone know what machine they are pulled from?)

Also that crystal (LBO) looks like its been exposed to moisture. Even having it in air can do that, they need to be sealed in a moisture proof unit (which they should be in the laser head). Unfortunately that means its ruined...I have seen LBO on ebay quite a few times, so I would say your chances of replacing it are high. I hope you can

Edit: check Meredith Instruments as well, they always have crystal sets of different kinds

 

[The Lightning Stalker]

When I removed the LBO/BBO (not sure which this is) I noticed that each end looked VERY scratched. Thoughts?

It's gone. That is what they look like when they have
absorbed atmospheric moisture. They need to be
hermetically sealed with a good dessicant. Take a
look at my profile pic. :beer:

 

[djQUAN]

Now I can forget about working with lasers like that.

If the crystals could be ruined in dry places like over there, imagine me opening one here in the humid tropics.

 

[ultimatekaiser]

I have a spare LBO you can use in there bloom. I preserved it pretty well. That ones clearly had a leak. Check the head seal.

 

[icecruncher]

Sam really likes you

473's are nice - my wife calls it the royal blue

I never liked the B&W Tek ones, I bought 3 of the cheap ones. But you are a brave soul working on them.

I got spoiled with the BLM-100, smaller PS and head, much cleaner beam.

Have fun playing with it.