wierd laser issues

[Abray]

so my Galileo 5 has been having this issue lately. It has developed a sort of scatter. or it mode hops. I can't tell. basically, when I turn it on, it seems almost normal, but then about a second later, a pattern becomes very defined around the dot. I am skeptical to call it mode hopping because there is still a very defined beam and dot, but all this scatter just comes from nowhere! It is also in a very distinct pattern! And if it is mode hopping, it has to be like TEM34 or something crazy...cause theres alot.

the last one isn't a very good picture, but the first two are pretty good examples. they came out pretty clear.
And as for the pictures, the dots or scatter is a little bit more defined in real life in the first two pictures. And if you look closely, you can see the dots pretty well in the third. so kinda put the two pictures together...lol and the first two are close ups from about 20 feet away. and that whole scatter region is about 6 inches wide where its very bright, and about 14 inches wide when it starts to fade away.



any help??????

 

[divindavid]

i think it is mode hopping have u tired to clean the lens?

 

[Abray]

i just tried to clean the lens, and its still the same. But if you think about it, it can't be dust or something on the lens cause It would be there from the start. But this pattern only appears after about a second or two.

I even just tried new batteries and its still the same

 

[RA_pierce]

I think what's happening is a combination of a dirty lens and mode hopping.

Just 2 days ago my X105 had a few specks of something on the IR filter so I had to disassemble the whole thing and clean it (what a pain in the ass there was a whole new set of problems that came out of that but I won't get into it...)... When it was dirty, I would turn it on, and it would appear normal, but as soon as the crystal warmed up, the mode changed to something in between TEM00 and TEM01 (an elliptical dot rather than perfectly round). When the mode changed, the beam grew a tiny bit, just enough for that one speck of something to block off part of that dot... so within 3 seconds the dot appeared similar to your pictures, maybe worse.

If cleaning the lens on the outside doesnt work (I would recommend a Q-tip and glass cleaner or windex; paper mught scratch the lens) the only solution I can think of is to disassemble the laser and clean every lens in the module. I have a Galileo also, and unless they changed the design, it should be easy to do. The top should unscrew, then the brass module should unscrew from the aluminum aperture cover, and the module should come apart in two pieces... the part at the top that contains the collimating lens is the part you want to unscrew... it might have a little glue, but it should come apart. You can then carefully and gently clean the inside of the collimator lens (use a new q-tip for each lens) and the one on the other half of the module. When you reassemble everything it should all be OK, if not, try it again (using new cotton swabs of course...) clean... dry... and if that still doesn't make a difference, I have no idea what's going on.

 

[Abray]

alright I fixed it! it was something on the lens, because I took a Q-tip to the lens, and now it seems to be back to normal! although it beats me how one speck on the lens makes that all around symmetrical scatter...

 

[CL_]

huh, sounds interesting