Waste beam question

[ltaudi1]

Ok here is the question, I recently made use of a gym I had access too off hours. I frequently go there to smaart and dial in my pa since they have ample 3 phase. Well I took my sp2011 over and setup to kinda play around and get some pix of since I had water to dump and plenty of power. I found an interesting thing though. Once I aligned the head and dialed it up to peak performance on the business end via the meter on the unit, I noticed that the waste-beam seems to be split out the back. The output from the front never diverges only the waste end, is this normal?

http://photonlexicon.com/forums/atta...1&d=1257428089

http://photonlexicon.com/forums/atta...1&d=1257428089

[ltaudi1]

Could the be from the lasing photons hitting an internal beam block, or the bore or something?

[mixedgas]

Could the be from the lasing photons hitting an internal beam block, or the bore or something?

Surface Ghosts, aka Fresnel reflections.

Back surface of the HR mirror reflects .05 % for rear ghosts Front surface of some output couplers looses another 1-4% as the ghost.
The optics have deliberate wedge between the two surfaces so the ghosts do not interfere with the main beam. Some lasers have AR coatings or sandblasted rear mirrors to kill the second surface ghost.

Steve

[Laser Ben]

Yeah, usually you will get multiple stray beams from the HR end of the laser, our I-90's at work have 3-4 beams out of the rear, however they are very low power and are hard to see. I have never noticed the beams from the OC.

Wedged and Birefringent optics/elements can do this to a beam. My Millennia has a pair of spots from the walkoff in the LBO, they are like 0.1 degrees from the main axis and are hard to see, but they are there.

[ltaudi1]

Thanks guys, I am a paranoid person and seeing this I got a little fidgety that something may be messed up in my most valued possession.