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Mirau White Light Interferometer. Light Source?

by adamjts
Tags: interferometer, laser, white light
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Jun9-14, 06:38 PM
P: 19
Hi everyone,
I'm building a white light interferometer and need help choosing and finding a white light source.

I'm using this mirau objective:

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Here is the setup:

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I know that the light source will have to be collimated and go through an aperture stop, field stop, bandpass, etc. I was hoping that there was a white light laser that does these steps already so that I don't have to work with several different lenses and build a setup for them. Such a laser must exist, no? Does anyone know where I can find one? Ideally one that is 100-200 Watts? I've looked all over but am having trouble finding an manufacturer that makes what I'm looking for.

Are there any important steps that I'm missing? Should a collimated white light beam do the job?

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Jun9-14, 08:56 PM
P: 115
200 Watts? (!) are you doing interferometry on the moon? That level of power on a laser is used to cut steel. Further, white lasers are a special purpose rarity. I've not heard of anyone using them for interferometry. Its not necessary. Why do you want to use white?
Jun10-14, 11:52 AM
P: 19
I'm not sure about the wattage but i know that white light interferometry is a common practice.

White light is more suited to rougher surfaces which would be appropriate for my purpose because the surface I'm looking at will have Ám variations.

Jun10-14, 12:06 PM
P: 19
Mirau White Light Interferometer. Light Source?

oh and yes I was totally off with the power of the laser
Jun10-14, 01:22 PM
P: 115
from what I've seen, white light interferometry is not done with a laser. And that includes your sources that you posted. reread the first page of your document from fp.optics. White lasers are a relatively recent invention. And I believe it is a much more complicated solution.
Jun10-14, 01:46 PM
P: 19
how to get a white light beam then?

I'm trying to figure out what these guys did:

just from the picture it looks like it might be an optical fibre?
Jun10-14, 01:48 PM
P: 19
I was under the impression that the steps described in the diagram (before the light even reaches the beam splitter) were steps that were typical of those carried out in a laser before it exits the laser.
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Jun10-14, 02:06 PM
P: 19
Do you think something like this might work?

Item MCWHL5-C2

I would probably need an aperture stop
Jun10-14, 02:37 PM
P: 115
Quote Quote by adamjts View Post
I was under the impression that the steps described in the diagram (before the light even reaches the beam splitter) were steps that were typical of those carried out in a laser before it exits the laser.
Attachment 70494
most of that is totally unnecessary if your light starts out monochromatic and coherent. For laser interferometry, all you need is the laser, a beam splitter, a lens, and a mirror.
Jun10-14, 02:58 PM
P: 19
that would be nice... but the white light VSI approach is necessary for the relatively rougher surface i'll be looking at.

Would you say that this light source:

with this beam splitter

and this mirau objective

could get the job done?
along with a CCD camera of course
Jun25-14, 09:55 AM
P: 1
Hi adamjts,

I'm a Product Support Engineer who works at Edmund Optics. I've been following your posts above and noticed that you're interested in White Light Interferometry. In terms of the setup that would go with the interferometry objective above, you're definitely on the right track. You would need an illumination source and a way to mount it inline. We have suggested parts for the illumination, inline mechanics, and the mounting. This would make sure that you don't have to build everything from scratch. If you're interested to discuss this further, please feel free to email me at this address. I look forward to working with you on your application.

Jun25-14, 05:01 PM
Sci Advisor
PF Gold
davenn's Avatar
P: 2,725
hi adamjts

on pages 18 and 19 of that document in your post #6

its shows their setup, they are using a white light LED ( Light Emitting Diode)


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