Advive about knife edging after cylinder correction

[kitatit]

Do you mean = in the far field or at the aperture?

[planters]

I would insert a wave plate, so the two P73 optical trains can otherwise be identical prior to the cube. This is easier than rotating everything 90 degrees and holding the expansion to produce perfectly square beams (as opposed to rectangular). Otherwise, sounds good.

[badger1666]

Hey kit near field beam should be stacked like two i 's sat on top of each other
They will fit the concave lens ok
When they exit the second convex lens the beam will be reshaped and look like this =
Then my first cylinder lens sits at 50 mm away from diode
This way saves a lens set , then you can just pbs and waveplate the red and blue together
My beam size at apteture is 4.5x 4.5mm

[jammah]

hi fellas,
badger, I had a quick question for you is that 50mm from the front face of daves diode mount or the front of the actual diode?
cheers
james

[badger1666]

I go from diode but its not that important
It just affects near field beam size
You can have them as close as you like if you want
Just remember smaller nearfield beam = bigger divergence
And larger nearfield = smaller divergence
Its just a case of preference and your scanner mirror size
I have big mirror dt's so i went for a 4.5mm beam @ 1.1 mrad

hi fellas,
badger, I had a quick question for you is that 50mm from the front face of daves diode mount or the front of the actual diode?
cheers
james

[kitatit]

I would insert a wave plate, so the two P73 optical trains can otherwise be identical prior to the cube. This is easier than rotating everything 90 degrees and holding the expansion to produce perfectly square beams (as opposed to rectangular). Otherwise, sounds good.

OK I have waveplate.... oh... its a 445nm one. bugger. I'll have to buy one.

Hey kit near field beam should be stacked like two i 's sat on top of each other
They will fit the concave lens ok
When they exit the second convex lens the beam will be reshaped and look like this =
Then my first cylinder lens sits at 50 mm away from diode
This way saves a lens set , then you can just pbs and waveplate the red and blue together
My beam size at apteture is 4.5x 4.5mm

Ah, cool I understand now. That's the orientation I have them.

hi fellas,
badger, I had a quick question for you is that 50mm from the front face of daves diode mount or the front of the actual diode?
cheers
james

Good question

I go from diode but its not that important
It just affects near field beam size
You can have them as close as you like if you want
Just remember smaller nearfield beam = bigger divergence
And larger nearfield = smaller divergence
Its just a case of preference and your scanner mirror size
I have big mirror dt's so i went for a 4.5mm beam @ 1.1 mrad

Great info. Things are getting clearer now

This is good to know. My project can tolerate a divergence of about 2-2.5 mrad. Now I know this relation ship I should be able to tweak it to get a smaller near field beam to fit through the motor shaft.

Hmm I'm torn between Planters duel cylinders, wave plate, psb cube then dichro and your knife edge with vertical stack, single shared cylinders, wave plate,then PSB cube.

Right I'll get drawing to see what it looks like.

Thanks a lot guys, I really appreciate you taking time to explain these concepts.

Cheers
Kit

[badger1666]

as for need of a wave plate either the red or the blue will need one , not both , depends on which colour hit the pbs face that needs rotating 90deg
kit stick with the blue for now as you have one, just orientate the cube so the red passes and use the wave plate on the blue
or just let the run thier paths and dichro them together ,and save the pbs and waveplate for another job