uniaxial crystal “ordinary index” “extraordinary index” call the unique direction z:...
TRANSCRIPT
Uniaxial crystal
o x yn n n
e zn n
“ordinary index”
“extraordinary index”
Call the unique direction z: “optic axis”
Ordinary wave or ray:Any wave with polarization E to the optic axis (OA).The wave travels with index no.Extraordinary wave or ray:Any wave with E component along OA! (polarization in the k-OA plane).The wave travels with index between no and ne, which we call the function ne(q). Angle q between k and OA
OA
General case: 2k’s, 2S’s
Crystals may be cut at any angle vs. the optic axis!
2 2 2 2( )
sin coso e
e
o e
n nn
n n
22 2
22 2 2 2 2 2
1yx z
o o e
uu u
nn n n n n n
Optic axis
kq
becomes
ne>no no>ne
For this cut of crystal and k vector shown, an e-wave is the ____a) s-polarization b) p-polarization c) both s,p are e-wavesd) neither s,p are e-waves
Don’t confuse s,p polarization with o,e polarization! No direct connection
OA
OA
For this cut of crystal and k vector shown, an e-wave is the ____a) s-polarization b) p-polarizationc) both s,p are e-wavesd) neither s,p are e-waves
Text gives equations for directions of S, E for ONLY the case in this picture: OA the interface….
Finding E, S directions for the extraordinary wave
so these equations aren’t very important…
OA
Finding E, B, S directions for the extraordinary wave
0 0
0 0
0 0
x x x
y o y y
z z z
P E
P E
P E
Gives ratios of E components
z
x
o
BS E
oo
k EB
0ok E P
What is to what?
EEOA E
S
oE P
k
Polarizing prisms
Good for high powered lasers.(no heating from absorption)
Cut and rejoin, with OA perhaps oriented differently.
Polarizing prisms from uniaxial crystals
In prism d, which exiting beam was the e-ray in the material it left?
a) topb) bottom
Polarizing prisms
In prism a, the the beams are separated by ___TIR
So in this material which index is greater?
a) n-eb) n-o
Polarizing prisms
In prism b, the beams (k’s) are separated by Snell’s law. Imagine the k-vectors are shown.
So in this material which index is greater?
a) n-eb) n-o