Production of Circularly Polarized Light, 519 



Taking f = — , we obtain the following law of refraction, — ■ 



sinyjr — fi . cosh rj (1) 



Also ^= - -\-TjL. 



For the vibration whose plane of polarization is in the 

 plane of incidence *, Fresnel's sine law becomes with the law 

 of refraction (1), 



sin (-v/r— - — rji) 

 b = a . ; 



IT 



sin (S/r-f - + r\i) 



" b " being the amplitude of the reflected, and " a " that of 

 the incident light. 



Writing b—r. e , we have 



6i_ cosQ/r— r)i) 



r.e -— a-cog^^^y 



. r „-e<_ fl 508(^+50 



COS {^jr — rjc) 



9 9 



Hence 



and c flc__ cos(f-q Q p m 



cos (ty + r)i>)' 

 For the component polarized perpendicular to the plane of 

 incidence, the tangent law becomes 



c= a . 



tan(i/r— - -^) 



TT 



tan (i/r-f- - + ^) 

 or writing c = r' . * \ 



cot (-^ + ^0' 



COt (a/t — 7^)' 



and as before we find r' = a, and 



^ t _ cot(^r— rji ) 

 COt (i/r -f- tjl) 



(3) 



* Fresnel's theory is assumed. 



