Clean-up time at MaXYZ

[marconi]

Aaron,, you kill me man...

Yeah, That'da make a good excuse...not likely.
I still have that big transmitter to deal with, thankfully the boss lives close by it..hehe.

Oh, the auction just now came up:
http://cgi.ebay.com/Prop-Effects-Blu...QQcmdZViewItem

[marconi]

Added a few more units for sale.. see top of thread

[Laser Ben]

Hey! Marconi! Check your PM inbox! I sent you a message about a new purchase.

[marconi]

Still have a few left over..
get-em while you can before I strip them for parts

[cruch]

What have you left?

[LaserLover]

Hi Rick;

Nah, that's against the laws of physics... Think about it: When you combine the first set of two beams (one vertically polarized and one horizontally polarized) you end up with a randomly polarized beam. Now you're stuck. You can't use another PBS cube to combine it with anything because half the beam will be rejected by the cube face...

Now, you can take the combined beam from one PBS cube and, using a knife-edge mirror, position it *extremely* close to a second combined beam from another PBS cube... What you end up with is a fat beam that is technically TEM01 in profile. In practice, with some shaping optics you can make it look fairly decent, but it's still going to be fatter than a single beam.

Marconi's quad rig takes advantage of this method, and the pics he posted of the beam profile look pretty damn good... I think the beam is still smaller (and lower divergence) than the 500 mw 635 nm diodes I've seen. (I'm looking forward to Marconi's official specs once he finalizes the quad design...)

Fuck - what we really need is a direct injection diode that makes a watt and a half of red at 640 nm with a 3 mm beam diameter and .5 mrad divergence. So someone go out and invent one already!

Adam

Hi Adam,

I recall an article by Dr. Christoph Bollig (Stellenbosch, Univ in South Africa ) who mentionned that If you combine 2 polarized laser beams through a PBS cube and mode lock both lasers the resulting polarities will be the same (It might be part of Sam's Laser FAQ's now). If you did the same to another pair of lasers (mode locked so the beams are in step with each other) you get the same polarity. Both those combined pairs could in turn be combined again into a PBS cube, etc....
But this is way beyond my budget or understanding of polarizing elements and laser physics, but apparently possible.

Rick

[steve-o]

How do you mode lock a diode laser?

[LaserLover]

How do you mode lock a diode laser?

Hi Steve,

As I said, It's beyond my knowledge of laser physics.
Here is a link to the original discussion about combining lasers that Dr. Christoph Bollig stated his theory. See " http://tinyurl.com/29fs29
"

Rick

[steve-o]

Hmm- looks heavy. I'll have to read that when i'm awake tomorrow- or the weekend heh--
probly beyond my knowledge (and comprehension) too..

[buffo]

Rick;

Outstanding find! I'm impressed by the physics... Thinking about it, I'm still surprised that it works, but I can't seem to poke a hole in it.

However, Dr. Bollig's willingness to attempt a re-creation of the experiment if someone was willing to provide $20,000 in funding speaks volumes about it's practicality. Sam Goldwasser sums it up nicely: "Like cutting down a tree to make one toothpick."

Still, it *is* cool that there is a way, at least in principle, for it to work - even if it's not at all practical. Thanks for the link to the article! (Sure hope it makes its way into the laser FAQ at some point...)

Adam