<s>
An	O
infrared	B-Algorithm
detector	I-Algorithm
is	O
a	O
detector	B-Application
that	O
reacts	O
to	O
infrared	O
(	O
IR	O
)	O
radiation	O
.	O
</s>
<s>
The	O
two	O
main	O
types	O
of	O
detectors	B-Application
are	O
thermal	O
and	O
photonic	O
(	O
photodetectors	O
)	O
.	O
</s>
<s>
Bolometers	B-Application
and	O
microbolometers	B-Algorithm
are	O
based	O
on	O
changes	O
in	O
resistance	O
.	O
</s>
<s>
In	O
IR	O
spectrometers	O
the	O
pyroelectric	O
detectors	B-Application
are	O
the	O
most	O
widespread	O
.	O
</s>
<s>
The	O
response	O
time	O
and	O
sensitivity	O
of	O
photonic	O
detectors	B-Application
can	O
be	O
much	O
higher	O
,	O
but	O
usually	O
these	O
have	O
to	O
be	O
cooled	O
to	O
cut	O
thermal	O
noise	O
.	O
</s>
<s>
In	O
photoconductive	O
detectors	B-Application
,	O
the	O
resistivity	O
of	O
the	O
detector	B-Application
element	O
is	O
monitored	O
.	O
</s>
<s>
Photovoltaic	O
detectors	B-Application
contain	O
a	O
p-n	O
junction	O
on	O
which	O
photoelectric	O
current	O
appears	O
upon	O
illumination	O
.	O
</s>
<s>
An	O
infrared	B-Algorithm
detector	I-Algorithm
is	O
hybridized	O
by	O
connecting	O
it	O
to	O
a	O
readout	O
integrated	O
circuit	O
with	O
indium	O
bumps	O
.	O
</s>
