SurplusShed - Prisms?

[rhd]

Quick question -

Has anyone come accross prisms on Surplus Shed that would be suitable for correcting 635 lab beams? I had it in my head that I didn't want a right angle prism - but this may not be correct, since it seems like most of the prisms ARE right angle prisms.

In particular, would these be appropriate?
RIGHT ANGLE PRISM 10MM X 14MM X 10MM - Surplus Shed
or
PRECISION 12.7MM RIGHT ANGLE PRISM FACES AR COATED - Surplus Shed

 

[steve001]

You are vague on exactly what you want to do.

 

[rhd]

You're right -

I'm looking to control the fast axis divergence on a multi-mode so that it's a little more manageable to get a dot instead of a line once it goes through the final collimating lens.

In other words, the same basic correct that people do in 445 labbies.
EDIT: Like this -

(From SELLING blue teccooled laser module)

 

[steve001]

Perhaps this
Wedge Prisms - Edmund Optics

 

[rhd]

Lol, there's a big difference between $4.50 spent at SurplusShed, and $61 spent at Edmunds

 

[rhd]

Upon doing a bit more research, I've realized that what I need are "anamorphic prisms".

I may post an inquiry over at PL, if nobody would consider it in poor taste to cross post.

 

[HIMNL9]

Uhm, they are not the right angle, and they don't say the diffraction index, but at least one of them say "AR coated" (just hope it's broadband AR, i doubt that can be blue AR, and IR coating is worse than nothing) ..... so at that price, can worth the expense to buy a pair of them and try (with a different angle than normal anamorphics, ofcourse)

 

[steve001]

Lol, there's a big difference between $4.50 spent at SurplusShed, and $61 spent at Edmunds

True, but EO takes away the guessing if these prisms will work. I suggest them because these come with known AR coatings. SSh says one prism is AR coated that's all. With the wrong AR or no AR coating you will lose quite a bit of light but you know that. You get what you pay for and you'll know that these EO prisms will perform to your expectations.

EO offers a lot of free info in their catalog and website which helps in making an informed purchase decision. Other companies from what I've seen don't offer as much.

Thor Labs carries them for less
http://www.thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=147&gclid=CMqUiNflj6kCFWVd5QodLTewrQ

 

[rhd]

True, but EO takes away the guessing if these prisms will work. I suggest them because these come with known AR coatings. SSh says one prism is AR coated that's all. With the wrong AR or no AR coating you will lose quite a bit of light but you know that. You get what you pay for and you'll know that these EO prisms will perform to your expectations.

I really do appreciate the help and input. Here though, it doesn't help me to be convinced on the quality side. I'm with you, I hear you. For this project, my budget doesn't allow for Edmunds or Thorlabs. That's why I posted the thread - I'm aware of those options. I need a DIY low end alternative. I'm just testing the concept of a design and some diodes with these, not intending to make a permanent labby.

HIMNL9: So what about using uncoated, right angle prisms. Would the geometry of that work?

 

[steve001]

I really do appreciate the help and input. Here though, it doesn't help me to be convinced on the quality side. I'm with you, I hear you. For this project, my budget doesn't allow for Edmunds or Thorlabs. That's why I posted the thread - I'm aware of those options. I need a DIY low end alternative. I'm just testing the concept of a design and some diodes with these, not intending to make a permanent labby.

HIMNL9: So what about using uncoated, right angle prisms. Would the geometry of that work?

Try here AnchorOptics.com - Supplies affordable, quality commercial grade and experimental grade optics

I'm far from knowledgeable about optics, but it seems like it would work if you can find the correct angle or close to it to cancel the fast axis of the beam. I'm assuming you want to circularize the beam. It would be somewhat more difficult to orient the prism accurately though unless you have some type of adjustable mount. Then again the anamorphic lens you mentioned might work as well or better.
Something I just came across DIY anamorphic lens

http://www.zuggsoft.com/theater/prism.htm There are several sources for these prisms. In the U.S., I have used Massillon Plaque.

Another type of lens option ? Plano-Convex (PCV) Cylinder Lenses http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=2110

or
Plano-concave (PCX)
http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productid=2107


More expensive so you'll have to shop around

 

[HIMNL9]

@ rhd: if they are uncoated, there's a good possibility that you loss a lot of power (maybe 20 or 25%), cause the faces acts as "splitters", reflecting a lot ..... if they are broadband coated, is not specific for blue, but is always better than nothing (and, probably, they are broadband coated, cause right angle prisms was used in binoculars for image inversion and "compact" the size of the binocular body).

If they are red or IR coated, they are worse than uncoated (IR coating reflect blue)


@ steve001: Anchor sell "wedge" prisms, but they are cylindricals, and this means you have to use a specific mounting set, for them (and is difficunt to align the rotation plane, too) ..... about the cylindrical lenses, i already thoughd about them, but the difficult, for a handheld mount, is to find a lens with the correct diameter and FL.

As example, the concave ones can be used for "enlarge" the slow axis, then you can use a bigger diameter lens for focus the resulting beam for distance (same as using a beam expander, but having it incorporated in the unit) ..... this, for the other side, prevent you to have a thin beam at short distance, or to have a burning spot at short range.

Positive (convex) lenses, can help you "squeezing" the fast axis, giving you a better thin beam at short distance, and a rounder shaped spot, but, ofcourse, increase a bit the divergence in long range ..... also, for be efficent and not change the whole assembly, it must be glued in front of the diode, and this require a "round shaped" cylindrical lens with 4mm to 5mm (max) diameter, one flat side, AR coating for 400 to 500 nm or similar, and a FL of 3mm to 3.5mm ..... other than this, it must be in glass, resisting to the heat (if you want to use it with 445nm diodes), and finally you need to align it on the top of your diode case and glue it with thermally resistent glue ..... this is basically the only way for use our 9mm lens holders and achieve a round beam in an handheld unit, without modify it.

The only other option is to use a larger front lens, but this give you the "beam expander" size beam, and also constrain you to modify all the "standard" existing heatsinks, modules and lens holders.

This ofcourse is not valid for labby style units, where you can have all the space you want.