refractive index petr Šafařík masaryk university: astrophysics institute of scientific...

Refractive index

Petr Šafařík

Petr ŠafaříkMasaryk university: Astrophysics

Institute of Scientific Instruments: Coherence Optics

E-mail:petos@mail.muni.czE-mail: petos@isibrno.cz

ICQ: 137-455-645Jabber:petos@physics.muni.cz

http://physics.muni.cz/~petos

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Theory

Definition of refractive index:The refractive index of a medium is defined as ratio

of the phase velocity in the reference medium to velocity in the medium itself.

Reference medium: usualy vacuum. Usually given the symbol n

Theory In case of light:

rrn 0r

rn

Phase & group velocity

kvp

kvg

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Methods of measuring

Indirect – Edlén‘s formula Direct – Laser refratometer

Methods of measuring

Indirect – Edlén‘s formula Direct – Laser refratometer

Indirect – Edlén‘s formula

p – pressure t – temperature (s-1) – dispersion coefficient

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t), (

t)p],-,([

,

)(t)(s-n

-

Weather bureau

Methods of measuring

Indirect – Edlén‘s formula Direct – Laser refratometer

Methods of measuring

Indirect – Edlén‘s formula Direct – Laser refratometer

Laser refractometer

Michelson‘s interferometr:

Laser refractometer Refractometr based on Michelson:

D - detector, L – laser, M – MirrorVP - Vacuum pump, VM - Vacuum meter , VS- Vacuum

sensor

Laser refractometer

Examples of interference fringes:

Fabry-Perot based refractometer

Scheme:

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

My results

Scheme:

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Summary Light rays chanfe direction, when they

cross the interface from material to other one by the Snellius law:

Light reflects partially from surfaces, that have refractive index fifferent from that of their suroundings.

sinsin 21 nn

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Outline

Theory of the refractive index Methods of measuring refractive

index My results at ISI Brno Summary Questions

Questions

Your time…