Handbook of Biomedical Optics

664 Handbook of Biomedical Optics

e factor C depends on the solid angle of collection (f) for the

transmitted light, and depends on the attenuation of the scat-

tered component by the tissue thickness, C = f exp(−

atten

L),

where 

atten

is the attenuation coecient for the scattered light

and is comparable to 

e

in diusion theory although the light

may not yet be fully diuse and 

atten

is less than 

e

. e degree

of linear polarization (p) behaves as

p

HQ

HI

HH HV

HH HV

T C T

T C

= =

−

+

=

+ −

+

( )

− −

( )

( )

+ −

− −

c c

2 2

c

e e

( )

(

1

1

2

1 1

1

χτ χτ

TT

T

c

2 2

2

c

e e

e as

)

1

2

1 1

0

+

( )

+ −

( )

( )

≈ →

− −

−

χτ χτ

χτ

(30.29)

Hence, the decay of p is initially inuenced by