DOC.
9
CRITICAL OPALESCENCE
245
__
_____(2nn~
N
C
V
3v2
V
®2y
(4icD)2
2
or,
if
we
consistently
introduce the
specific
volume
v
and
replace c/n
by
the
wavelength
A
of the
excitory light,
*5
^0
[ay]
f2itV
$
(17)
ty
=
iV
32ijr
U
J
(4itD)2
2
dv2
Here $ denotes the
opalescence-producing
volume
traversed
by
the
light,
the
shape
of
which volume is
of
no consequence.
An
analogous
formula
holds
for the
z-component,
while
the
x-component
of
e
vanishes.
From
this
we see
that,
for
determining
the
intensity
and the
polarization
state
of the
opalescence
light
emitted
in
a given
direction,
the
decisive
factor
is
the
projection
of the electric
vector
on
the
plane
normal
to
the
opalescence
ray, no
matter in what
direction the
exciting light may propagate.7
If
Je
denotes the
intensity
of the
exciting light,
J0
the
intensity
of the
opalescent
light
at
a
distance
D
in
a specified
direction
from
the
place
of
excitation,
and
p
the
angle
between the electric
vector
of
the
exciting light
and the
plane
normal
to
the
opalescence
ray
under
consideration,
then
we
will
have, according
to
(17),
tin \
J° RT°
ldvM2*Y
b
2
(17a)
-
=
_-\
'
|_|
_
_
coszp
Je
N
32i|;
U
J
(4itD)
In
addition,
we
will calculate
the
apparent absorption
due
to
opalescence
by
integrating
the
opalescent
light over
all directions.
If
the
thickness of
the
layer
traversed
by
the
light
is
denoted
by
5
and the
absorption
constant
by a (e"6
=
intensity
attenuation
factor),
we
get
(18)
a
=
6%
N
f2icN4
A.
dv2
[18]
7
It
is
not
surprising
that
our opalescence light
shares
this
property
with
the
opalescent
light
produced
by
suspended
particles
that
are
small
compared
with
the
wavelength
of the
light.
After
all,
both
cases
involve
irregular
disturbances
of the
homogeneity
of the irradiated
substance,
the locations of
which
are rapidly changing.