1/2 wave plates are ready to go

[CDBEAM]

Please reserve one (1) 1/2 waveplate for use in a 445nm Quad set up. Thanx !!

CDBEAM ( Bob )

[dave]

Also interested in a couple of 650nm waveplates.

but can you be a little bit more clear about "very little loss"
I still remember the old laserwave dichro's with "very little loss"

Is it possible to get thicker waveplates? as a 0,5mm wave plate can break very easy

A quick measurement I did with a 445 diode, a pbs and a 1/2 wave plate, and I got around 1-2% loss. Its hard to say whether the losses were the waveplate, or the PBS or ore likely a combo of the both.

We can get thicker waveplates, but they will be multi order wave plates, as opposed to low order waveplates like these ones. Now I understand low order are better? Can any one comment on this?

If thickness is a issue, perhaps i can design up and get a small retainer ring made up?

[dave]

how is a wave plate set up for use ??
does it need to be the right way around to use ??
does in need rotating so the polarisation is correct for use with a pbs ??
will it need a special mount to acheive the above ??

if anyone could let me know the rules to using one of these would be cool

You rotate the wave plate to rotate polarisation - As easy as that. You shouldn't need a special mount, but I am considering some form of mounting hardware.

[dave]

Ill start a buyers list shortly.

[dnar]

Dave, from my understanding you would place one of these just before the PBS right? Rotating the polarisation of a knife edge set.

Why not design a mount for both wave plate AND PBS combined?

[krazer]

I would be in for 2x 445, 1x 532nm, and 1x 640nm

[kl79]

Hi,

1 x 640nm for me.

Regards
Mickael

[Jem]

Now I understand low order are better? Can any one comment on this?

Edmund Optics put this much more eloquently than I ever could...

"Multiple Order Waveplates and Zero Order Waveplates are interchangeable. Zero Order Waveplates should be considered for more critical applications. The advantages of a Zero Order Waveplate are an increased bandwidth and a lower sensitivity to temperature changes. A ±2% change from the design wavelength will cause only a minor change in the retardation of a Zero Order Waveplate. With a Multiple Order Waveplate, a ±1% change from the designed wavelength will cause considerable problems with the retardation."

As i'm wanting to use the 640nm waveplates with a 632.8nm HeNe for holograhy, in my case, it's essential that the waveplates are zero order. The 532nm waveplates I would be using with a 532nm laser so that's not as critical, although zero order would obviously be preferable.

If thickness is a issue, perhaps i can design up and get a small retainer ring made up?

That would be a much better proposition, and make the plates much easier to handle safely, if you are able to, and don't mind organising it .

Cheers

Jem

[mccarrot]

Can't we get a PBS with a waveplate already glued (with optical glue) on one side.

[RedlumX]

"Multiple Order Waveplates and Zero Order Waveplates are interchangeable. Zero Order Waveplates should be considered for more critical applications. The advantages of a Zero Order Waveplate are an increased bandwidth and a lower sensitivity to temperature changes. A ±2% change from the design wavelength will cause only a minor change in the retardation of a Zero Order Waveplate. With a Multiple Order Waveplate, a ±1% change from the designed wavelength will cause considerable problems with the retardation."

It depends on the application. Normally a good waveplate can achieve an extinction ratio of, let's say 1000:1, which is nowhere needed in hobby applications; (it may be needed eg in Faraday Isolators where one needs a high polarization purity). Probably 20:1 or so is all what one would ever need in holography. Which means that one can tolerate a larger deviation from the nominal wavelength, and/or stick with cheaper multiorder plates. In fact, the thicker the more stable they are, which is another reason for multiorder plates.

I use a multiorder HeNe plate (633nm) for my Opnext diode (640nm), I had at first checked the extinction ratio and it was so high that I could almost completely extinguish the beam when sending it through a polarisator. So it's really not that critical.