how ro pump a 473nm crystal assembly?

[Draco]

I have enough parts to make an attempt, the crystal i believe has a rating of 10mw so i am glad you guys warned me about the pump power so when i figure the wiring pin out to the head i will try to energize it with a 1 watt that may or may not still work, but luckily it's a C-mount

[kecked]

After all the effort you might want to just buy one of the new shortwave length blue diodes and toss the thing.

[Draco]

That's not the point.
I know i can get a diode that can be very cool, but this is a technical exercise so i can learn more about how these lasers work regardless of there obsolescence, ever since i have seen one working in person i have always wanted one.
and i also find it to be fun, aside from accidentally setting something on fire with the pump source
(With IR glasses on of course)

it would be running by now but i had a set back, the cathode popped off and i killed the diode trying to repair it, that brings me to a second question, i have a 1 watt that some times mode hops, the laser it's in experinces a spike in current at power up, the engine for some reason did not put a delay, that diode has a FAC lens, i am thinking i may need to take that off as the orginal did not have it and the optical path has the normal corrective optics and correction prisms.

Will it work with the FAC still on the diode? i would hate to take that off considering i paid a little extra for it, and the laser it's in that part is needed but i am going to replace that with a 2 watter, it's in a green dpss but sinve the power supply slams it so hard i use a 2 watt, i have had good luck with that and the driver can accommodate the higher threshold current, it gives me more overhead for that spike, a lasorb helps but not totally


Thank

[aimpertro]

This lasing cell originates from a B&W Tek BWB-10-OEM Laser Head, which is actually a rebranded CNI Head.
The output was regulated by the driver to be 10mW@473nm using a feedback circuit, but certain users could get up to 100mW output from this cell, but this depends strongly on your certain item.
Originally, there was a 2W+ 808nm diode used to pump the Nd:YVO4 excitation band. An anamorphic prism pair and some lenses were used to focus the pump light onto the small YVO4 crystal sitting in the brazen part of the cell. The big crystal is just the LBO doubler.
If you google the name, there will be a lot resources and pictures concerning the components.

[Draco]

I was wondering what the power rating was, just got the other parts that i did not have when i started the tread, i guess my 2 watt diode is back into play, i did Google it and found a ton of info! i have two crystals now and some more info on the head, mine has the crystal's TEC is hooked up backwards, i even found some old threads here

I have a good idea now to why my past attempt to get the crystal i put pictures of to lase, i think the focal length of what i was using was wrong, i had it too far away

yeah i see some people getting at least 30mw, on mine i dont have plans todo that i just want it to lase and be stable, i have yet to find out what the leds indicate though.

that brings me back to what JRGixxerfreaK1 told me about this possibly being hygroscopic? is there a way to inspect that? does the crystal discolor or have any defects i can see?
I had a crystal fail on a 2 watt DPSS but it was very obvious

[aimpertro]

I don't know about any hygroscopic defects that can be observed by the naked eye, but the hygroscopicity of the LBO Crystal will only become a problem when exposed for longer times (speaking of several months) in non-dry areas.

To be on the safe side, you could place silica gel bags near the crystal, but I doubt this would be very helpful. When you place the plastic cover back after your working time, everything should be okay.

Additionally, the optical surfaces of the crystal are protected by the Antireflex coatings, so no need to worry.

[Draco]

Thanks for the info. I was able to get some beam today, it was weak and unstable but i got something! My pump diode has an FAC on it and suspect that is a problem but i got something, i can also see a beam in the infared (with a camera) and it's slightly off axis from the crystal so i need a diode with no FAC and an alignment, I love bringing something back from a scrap heap

[Draco]

I would just pop off the FAC but that diode is distend for a green laser that needs the FAC, i dont totaly know if that is my problem though, i know alignment is now a future project, maby even today if i get my lazy tail into action,the laser it's going in slams the diode with a nice spike in the drive, and a LASORB knocks it down a bit, the laser does not have a beam delay and i have no clue why some engineer thought it was good to not have a delay, this is my second laser with that fault, the drive can provide more then enough current for using a diode of 2 watt instead of a 1 watt that i believe it came with

i have also found out the hard way on how stupidly sensitive these are to static electricity, i ground my self is an ankle strap and a conductive lab coat, oddly i obtained 3 lab coats, one is from a former employer and the others i got on my own, i had gotten them for fireworks and then electronics for a side use, i cant find my one coat from when i worked at Sony, i always joked that it made us look like smurfs, granted over stressed smurfs that love booze a bit too much. \

I am tempted to use the working 1 watt diode but i believe it would have a short life and not worth the risk. The higher power guts from a 300mw pointer will be mated with the optics and crystal, in another post i found that aluminum to aluminum is not ideal for threads, they sized, it will an odd experment

I never did get an answerer for that diode that has an FAC in this laser that never had one on the diode, but this is a very educational exercise and since i got a flash i am confident i canbeat this thing working, later on when i can afford it i will get a diode from DTR that is close to this laser, i really love the color

[planters]

Your question about the FAC is difficult for me to answer. How does the 808nm diode pump feed the crystal? If this is an engineering exercise rather than just an attempt to restart an old dpss laser, I'm all for it. You might step the diode back and with or without the FAC you can use macroscopic optics to shape the beam to mach the input face. Use a separate diode driver such as a Flexmod. Use thermal epoxy to attach a small thermistor to the diode heat sink and to the crystal mounting block. Drive each of the TECs with a thermal controller of just about as easily by bench top power supplies.

Now you can analyze the parameters for the different variables. You can max the IR at 946nm independently. This would be done prior to tweaking the position of the LBO.

[Draco]

The diode is right up agenst an optic , the face that the diode is next to optic that is flat on the side that faces the diode, that then goes to a prism pair and then into another lens set before the crystal assembly, i cant tell of the two crystals are bonded or not as it's in it's own housing with an input mirror and an exit mirror, i think if i try to take that assembly apart i would damage it beyond repair. The main parts look typical of other better quality DPSS Lasers.
I do have a tec controller but i am wondering what temp should i run the crystal at?
I think the diode is temp controlled for 808.5nm from the data i was able to find. I was thinking about disconnecting the diode and using a flexmod just as you suggested, i only have one on hand and that i think will work great, I have no idea what the controller is doing and it may have a fault as it sits now.
I think i going to need to order a second diode with out a FAC, the one i have is destined to be installed into a green DPSS that needs the FAC, i will have that unit's diode but it's only 1 watt, I dont know if it's even enough power, once i find my thermal epoxy i will liberate that diode from it's abusive controller and try that with a flex mod and the FAC on the 1 watt removed