online optical calculator logo
tutorials



plane refracting surface

Two transparent media with different refraction indexes n0 and n1 are separated with a plane interface (plane refracting surface). n0 and n1 are equal or larger than 1. n0 or n1 can be equal to 1 if the corresponding medium is air or vaccuum. Actually, vacuum index is very slightly smaller than 1 but is commonly approximated to 1.

refraction angle through a plane refracting surface

refraction on a plane refracting surface

Light rays propagating from the first medium (refraction index n0 ) to the second medium ( refraction index n1 ) are deviated at the plane interface. A light ray coming from the first medium with an angle of incidence i ( angle between the light ray and the normal to the interface ) is then transmitted ( refracted ) at the interface and propagates in the second medium with an angle of refraction ir different from i. Incident light ray, refracted light ray and normal to the surface are in the same plane.

ir depends on i, n0 and n1.

total reflection on a plane refracting surface

reflection on a plane refracting surface

Most of time, light is not only transmitted at the interface. Generally, part of the incident light is also reflected. Ratio of the reflected light by the plane refracting surface depends at least on media refraction indexes and on the angle of incidence. If n0 is larger than n1, total reflection occurs (no light is transmitted through the plane refracting surface ) when the angle of incidence is larger than a certain value it ( minimum angle of incidence for total reflection ).


it depends only on n0 and n1.

References

"Optique Fondements et applications" - 2004 - author : José-Philippe Perez.

"Optique géométrique Imagerie et instruments" - 2007 - author : Bernard Balland.

"Optique géométrique paraxiale" - Institut d'optique théorique et appliquée - 1985 - author : Michel Cagnet.

"Formation des images Aberrations" - Institut d'optique théorique et appliquée - 1985 - author : Michel Cagnet.



contact : contact@optical-calculation.com - website : www.optical-calculation.com Copyright © 2009 CLAVIS S.A.R.L. All rights reserved