Entrance fiber parameters

Benjamin Viquerat

Prodigy 120 points

Hi everybody,

I plan to use a fiber to get the light to be analysed into the NIRSCAN.

What parameters should I use?

The input slit width is 25µm. I guess the core diameter of the fiber should be at least a few times bigger than this, let's say at least 100µm.
Would 1000µm be a too big diameter core? Is there actually a limit for this parameter?
The numerical aperture of the fiber should be bigger than the NIRSCAN's one. What is actually the NIRSCAN's one? Again, what would be a good choice of NA here? 0.22, 0.39, 0.48?

Thanks for any advice.

Benjamin

over 10 years ago

0 Benjamin Viquerat over 10 years ago

Prodigy 120 points

I tried a Multimode fiber 1000µm core diameter NA 0.48 and it seemed to work pretty well.

I didn't experience any wavelength shift.

Has anyone tried a fiber input as well ?

I'd be interested in any similar feedback.

Benjamin

0 Tom Myers2 over 10 years ago in reply to Benjamin Viquerat

Intellectual 475 points

Hi Benjamin,

I have not tried this yet, but plan to.

I have been researching using a refelectance probe and looking at a fibre bundle where one end is a circular collection of fibres and the other end the fibres are arranged in a linear 1-D array which should help the distribution of light across the slit.

Have you considered this?

Thanks,

Tom

0 Benjamin Viquerat over 10 years ago in reply to Tom Myers2

Prodigy 120 points

Hi Tom

No I haven't tried that.

Do you get good results with the NIRSCAN in reflectance configuration?

I don't know about the sensitivity of the spectrometer since there is no corresponding setting (gain, integration time, ...)

Did you use the existing lamp or did you need a more powerful light source?

Thanks

Benjamin

0 Tom Myers2 over 10 years ago in reply to Benjamin Viquerat

Intellectual 475 points

Hi Benjamin,

I have not tried this configuration yet, I am still designing it.

I propose to use a laser though.

Thanks,

Tom

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Entrance fiber parameters