
44-26 Optical
andSiC(4H) [85–87]. Note that the reectance is plotted on a linear scale, whereas the absorption
coecient is plotted on a log scale.
As se
en
in th
e
pl
ot
fo
r
Ga
As,
wh
ich
is Al
x
Ga
1–x
As for x = 0, the absorption depths at 320 and 380 nm
are 75 and 72 μm, respectively. is suggests that a “dead layer” of more than 10 nm would have a sig-
nicant
im
pact
on re
ducing
th
e
DE fo
r
th
ese
wa
velengths
. e ab
sorption
de
pths
at 32
0
an
d
38
0
nm fo
r
Al
0.8
Ga
0.2
As are 80 and 20 μm, respectively. is suggests that a “dead layer” of 10 nm would eectively
block 320 nm, but some 380 nm light would pass through. e values for the absorption depths