How can I fix (do it yourself) this IPG fiber laser?

[GregR]

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This laser, along with a lot of other equipment, was removed as a component for sale on eBay. The disassemblymen are skilled with plyers.

Any suggestions appreciated.

[krazer]

Post some pictures of the inside of the laser, in particular the piece of optical fiber before the spot where it has been cut and we can survey the damage

[hologeek]

The output coupler mirror was probably on the end of the fiber that was cut off. You at least have a 915-975nm pump diode, LDD and TEC controller.
You might be able to polish the end of the fiber to get it to lase, acting like a weak OC.

[GregR]

Post some pictures of the inside of the laser, in particular the piece of optical fiber before the spot where it has been cut and we can survey the damage

It will be a number of days until I receive the laser and am able to disassemble for photos. The laser was shipped from the seller today.

[GregR]

Is it fair to say that if the output coupler was at the end of the fiber, then the fiber coming out of the enclosure was doing some of the amplifying to get 20 watts? If this is the case, then would the laser need the same secretly doped fiber that it had originally? A few years back I visited Nufern in Connecticut and they claimed to have sold fibers to IPG then were no longer doing it as IPG brought it inhouse. Now, Rofin bought Nufern and they sell a very similar product. And, Nufern will sell fiber, but the buyer needs to specify the fiber make-up. Anyone know any more about the fibers and fiber sources that may work?

[GregR]

My apologies for posting this question within the wrong category on photonlexicon--it has been more than a year since I read the categories.

The YLP brochure says that the fiber length changes with pulse power. My interpretation is that this means the factory cuts the fiber to the length best suited for a particular output pulse energy.

The brochure goes on to say that the fiber is terminated with a collimator. My interpretation here is that the output coupler is upstream, prior to this fiber connection.



For the YLP product brochure says,
Standard YLP Series Ytterbium laser modules provide a
pulsed output beam with average output power from 5 to
100 Watts and pulse width from 80 to 500ns. Laser output is
provided by a 1 to 8 meter (depends on energy per pulse)
metal-sheathed optical fiber cable terminated by beam col-
limator providing a near diffraction limited (M2<2) beam
with diameter from 2 to 15mm.

[VDX]

... I have some broken CW-fiberlasers - the fiber is the laser resonator with maybe 30 single-emitter pumping diodes with 975nm and either 5Watts or 9Watts power each (sometimes 25Watts too).

The pumping diodes are injecting their energy through 105 micron thick fibers into the cladding of the resonator fiber to pump the 50 microns thick core ... don't know, how much of the pumping energy will emit from the broken+polished end of the resonator fibre when running. But the firmware will detect the 'failure' of the resonator and won't let the laser power up though!

I'm salvaging the pumping diodes for using them solely (or more combined for higher powers) in different applications from laser-engraving to SLS ...

Viktor

[GregR]

Post some pictures of the inside of the laser, in particular the piece of optical fiber before the spot where it has been cut and we can survey the damage

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One picture shows something that feels like oil. Not sure what it is and how it got there.

[GregR]

Viktor, that sounds interesting. I found another picture on the internet that shows another laser. Are these diodes the same as the single emitter pumping diodes with 975 nm that you use?

661295280_o.jpg
661295287_o.jpg
661295296_o.jpg
661295302_o.jpg

Can you describe the path from the diode to the fiber?
The electrical seems to daisy chain. How are the diodes powered? Are they timed in some way or simply just all powered on all the time?

[VDX]

Hi GregR,

the diodes in your last post are old 5Watt@5Amps-diodes (PLD-5) - here you can find some infos for driving them: http://reprap.org/wiki/Laser_Cutter

The laser resonator-fiber is connected with side-splicings - should be a bunch of small (2mm wide, 20mm long) square tube pieces around the resonator fiber, where the individual diodes are injecting their energy.

I don't think you can use the original fiber or electronics, as it's a closed loop system with pumping and measuring/regulating the actual energy level.

For using the single diodes I'm braking the fiber end to a clean perpendicular end-surface (or again, if the previous attempt wasn't successfull) and place a lens before the end, so the focussed beam has the properties I need (spot diameter and distance).

Driving is really simple with constant-current drivers ... you only have to avoid voltage spikes when switching the current or electrostatic disscharging on the 'open' diode pins ...

Viktor