Announcements 1/23/12


Prayer
SPS social
Reading Quiz

When a plane wave hits an interface between two
different materials, which of the following wave
properties will change from the incident to the
transmitted wave:
a. Amplitude
b. Frequency
c. Direction
d. Two of the above
e. None of the above
Reading Quiz

The Fresnel coefficients r and t (not R and T):
a. Describe how much electric field is reflected and
transmitted at an interface
b. Describe how much intensity is reflected and
transmitted at an interface
c. Must add up to 1
d. More than one of the above
e. None of the above
Boundary Conditions
1
  D  0 (if  free  0)
B  0
2
 1 E1   2 E2
 B1  B2 
B
 E  
 E1/ /  E2/ /
t
B1/ / B2/ /
D
 H 
(if J free  0) 

t
1
2
 B1/ /  B2/ /
(if H ~ B)
(if 1 = 2)
Reading Quiz

When a light ray hits an surface, the plane
which contains the incoming, reflected, and
transmitted beams, is called the “plane of
_________”:
a. incidence
b. interface
c. intersection
d. reflection
e. refraction
Reading Quiz

To represent the two polarizations that are
parallel and perpendicular to the place of
incidence, we use the symbols:
a. n and w
b. p and q
c. r and u
d. s and p
e. t and v
Reflection/transmission for normal incidence
Energy/power coefficients
At an angle!
1
q1R
q1I
q2T
2
y
z
(x into board)
s-polarization: full treatment (handout)
1
q1R
q1I
q2T
2
y
z
(x into board)
Fresnel Equations, summary

If near perpendicular (1-D problem)
v2  v1 n1  n2
r

v1  v2 n1  n2
2v2
2n1
t

v1  v2 n1  n2
R r

2
T  1 r
2
For arbitrary angle
with
1  
rs  polar . 
1  
2
ts  polar . 
1  
 
rp  polar . 
 
2
t p  polar . 
 
cosq2
cosq1
n
 2
n1

Setting up HW problem P3.1