Polarized Raman Spectroscopy: Understanding the Magic Angle

[Smerdiis]

Dear friends
I have a question regarding to polarized Raman spectroscopy. When we are talking about parallel and perpendicular electric field of the laser, is the magic angle 90° or 54.7°?
I'd be grateful if you could answer me as soon as possible.
Best wishes
Kasra

 

[DrDu]

Maybe you can explain this in more detail. I know the term "magic angle" from nuclear resonance, but not from Raman spectroscopy. However, it may be easy to figure out what is meant in that context.

 

[Smerdiis]

Dear DrDu

The magic-angle in Raman spectroscopy or Linear Dicroism is the difference in the electric field of two different incident light polarizations.

Thanks

 

[DrDu]

A difference of electric fields hardly has the unit of an angle?

 

[Smerdiis]

oh actually it has
when you linearly polarise the light, you are rotating and adjusting its electric field to a specific angle
This is the base of techniques such as linear dichroism, circular dicroism, polarised Raman spectroscopy and polarised IR spectroscopy.

 

[Huastecan]

I've heard the term "magic angle" for NMR, and is around 54°. For Raman a perpendicular angle would be 90°.

 

[Smerdiis]

I guess so
Thank you very much

 

[Claude Bile]

Dear DrDu

The magic-angle in Raman spectroscopy or Linear Dicroism is the difference in the electric field of two different incident light polarizations.

Thanks

I think Smerdiis meant to say phase difference which would indeed have angular units.

Claude.