Jump to content

DIY Fourier Transform Spectrometer in Visible range


Recommended Posts

I want to make an Fourier Transform Spectrometer in the visible range. I am having problems with finding a proper linear stage.

The wavelength range is 400-1100nm, which makes out the smallest resolution and accuracy should be better than 150nm.

The wavelength resolution at 1100nm should be 1nm, which works out the track length to be greather than 2mm.

The system f# makes that the mirror should be of 50mm size, which makes its weight to be 50g.

I don't want to get into the argument that a dispersive system is better. I know that.

Please help me find a component which will help me displace 50g weight at a resolution of <150nm for a total track length of >2mm.

Thank you for your time.


Link to comment
Share on other sites

Ok, that's a reasonable sum. You should be able to get a decent stepper motor stage for that. My experience is with THz TDS rather than Fourier spectrometet, how repeatable do you need the position to be, is a min increment of 0.1um ok or do you need the reversible position accuracy to be similar?

Link to comment
Share on other sites

The resolution as well as bi directional repeatability and accuracy should be <0.15um. Just getting the resolution has no value if the true value is way off.

I am looking at some Piezo electric inertia actuators in Thorlabs (Thanks for that). Also Newport has some of those.

They are fulfilling my requirements.


Link to comment
Share on other sites

Newport would have been my second look. And given your reply I would have indeed pointed you towards piezo devices.


Good luck and let us know how it goes. I love spectrometers. Just a shame I don't get to play with them anymore.

Link to comment
Share on other sites

Have you guys ever made one?

@John Cuthber: do you know the major issues which will be faced while making one? Or any mistakes which I could make...

One more question, which kind of beam splitter can I use?

I want it to be :

polarisation insensitive

clear aperture: >38mm


wavelength range=(less than 400nm) to (greater than 1100nm)


I zeroed in on https://www.thorlabs.com/thorproduct.cfm?partnumber=BSW27


are there any better options I might have missed, or a type of beam splitter I should rather look into.

There are also these cube beam splitters which could also do the job, but I don't know how they compare with plate beam splitters.

Thanks for your time guys.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.