Green Module from PLUTO II - Fuzzy Output

[djeric68]

Hey guys!

Can anyone give me direction on what to do to realign this green module from my Pluto II?


This happened when it was new, and they sent me a new Green module & power supply to swap in.

Is this an easy fix to realign the lenses? Which lense to adjust? Or is the diode itself damaged?

This has been on my shelf with its power supply for years and I'd like to fix it and either put it in a mobolazer g-beam i have or build it into part of a lumia rig.

Here are the good pics from inside....



Do I need to carefully adjust/mess with #1, #2, #3, #4, #5, or ALL of the Above?

Thanks in advance for any help and tips!

[buffo]

Hi Eric;

I've never seen a Pluto II green module do that before. That being said, the first thing I'd try adjusting would be the primary collimating lens (#3 in your picture). It's threaded, so you should be able to screw it in and out slightly. See if a half-turn or less in either direction makes the problem better or worse.

I think it would be very unlikely for any of the other adjustments to get knocked out of alignment, unless you notice that one or more of the screws are clearly not snugged down tightly. (I'd check them one by one just to be sure, always in the "tighten" direction.) If you do find a loose screw, then you might try loosening the rest of the screws on that element alone and then tweaking the position a bit to see if it helps, but again, this seems like a longshot.

Did this slowly get worse over time, or did you just plug it in one day and notice that the beam was a lot fatter than before? (Or was it hosed right out of the box?)

Unless it's a simple issue with the primary collimating lens, I'm guessing that the diode emitter face itself has been damaged. And if that's the case, then that sucks, because the only fix is to replace the diode.

Although since this is basically a free laser for you, even if you have to replace the diode that might not be so bad. (DTR's laser shop sells several bare, high power, direct-injection green laser diodes for ~ $70-100.)

Adam

[mixedgas]

Be glad that you have a re-workable module that is reasonably well made. I've seen far worse then that.

There is a slight chance that the epoxy "relaxed" on the cylindrical lens mount over time. In which case, thin steel shim stock (.001 inch or .005 inch) from McMaster-Carr becomes very useful to correct any lens tilt. You shim the lens by putting stock under it's base. Check the optics for dust inside the collimator. Otherwise Buffo nailed it.

Steve

[djeric68]

I've never seen a Pluto II green module do that before. That being said, the first thing I'd try adjusting would be the primary collimating lens (#3 in your picture). It's threaded, so you should be able to screw it in and out slightly. See if a half-turn or less in either direction makes the problem better or worse.

I will try that.

Did this slowly get worse over time, or did you just plug it in one day and notice that the beam was a lot fatter than before? (Or was it hosed right out of the box?)

I was fine when I first got it, but within a few months of use (about 18hours total) it showed up, got a little worse, and then stopped at its current state. The PLUTO was always carried in it's flight case, and was never dropped.

Unless it's a simple issue with the primary collimating lens, I'm guessing that the diode emitter face itself has been damaged. And if that's the case, then that sucks, because the only fix is to replace the diode.
Although since this is basically a free laser for you, even if you have to replace the diode that might not be so bad. (DTR's laser shop sells several bare, high power, direct-injection green laser diodes for ~ $70-100.)

I would be happy using a DTR diode if this one is bad, just not sure of how to mount & align everything afterwards. Time to start reading up...

[djeric68]

Be glad that you have a re-workable module that is reasonably well made. I've seen far worse then that.

There is a slight chance that the epoxy "relaxed" on the cylindrical lens mount over time. In which case, thin steel shim stock (.001 inch or .005 inch) from McMaster-Carr becomes very useful to correct any lens tilt. You shim the lens by putting stock under it's base. Check the optics for dust inside the collimator. Otherwise Buffo nailed it.

Steve

Thanks Steve & Adam. Good info about the steel shim stock. I always have trouble getting things the exact right height in the projectors I have built or "upgraded" and got dissappointing results using washers, sheet metal, hex nuts and all-thread, etc. I'll check the collimator for adjustment and dust. Hopefully it's an easy fix.

I'll work on it later today and post the results!