<s>
All-silica	B-Device
fiber	I-Device
,	O
or	O
silica-silica	B-Device
fiber	I-Device
,	O
is	O
an	O
optical	B-Architecture
fiber	I-Architecture
whose	O
core	B-Device
and	O
cladding	B-Device
are	O
made	O
of	O
silica	O
glass	O
.	O
</s>
<s>
The	O
refractive	O
index	O
of	O
the	O
core	B-Device
glass	O
is	O
higher	O
than	O
that	O
of	O
the	O
cladding	B-Device
.	O
</s>
<s>
These	O
fibers	O
are	O
typically	O
step-index	B-Device
fibers	I-Device
.	O
</s>
<s>
The	O
cladding	B-Device
of	O
an	O
all-silica	B-Device
fiber	I-Device
should	O
not	O
be	O
confused	O
with	O
the	O
polymer	B-Language
overcoat	O
of	O
the	O
fiber	O
.	O
</s>
<s>
All-silica	B-Device
fiber	I-Device
is	O
usually	O
used	O
as	O
the	O
medium	O
for	O
the	O
purpose	O
of	O
transmitting	O
optical	O
signals	O
.	O
</s>
<s>
The	O
practical	O
application	O
of	O
optical	B-Architecture
fibers	I-Architecture
in	O
various	O
optical	O
networks	O
determines	O
the	O
requirements	O
for	O
the	O
technical	O
performance	O
of	O
optical	B-Architecture
fibers	I-Architecture
.	O
</s>
<s>
For	O
short-distance	O
fiber-optic	B-Architecture
transmission	O
networks	O
,	O
the	O
multi-mode	B-Device
optical	I-Device
fiber	I-Device
is	O
suitable	O
for	O
laser	O
transmission	O
and	O
wider	O
bandwidths	O
,	O
so	O
as	O
to	O
support	O
larger	O
capacity	O
of	O
serial	O
signal	O
information	O
transmission	O
.	O
</s>
<s>
For	O
long-distance	O
submarine	O
optical	O
cable	O
transmission	O
systems	O
,	O
in	O
order	O
to	O
reduce	O
the	O
number	O
of	O
expensive	O
optical	B-Architecture
fiber	I-Architecture
amplifiers	O
,	O
it	O
is	O
important	O
to	O
consider	O
using	O
optical	B-Architecture
fibers	I-Architecture
with	O
large	O
mode	O
field	O
diameter	O
area	O
and	O
negative	O
dispersion	O
to	O
increase	O
the	O
transmission	O
distance	O
.	O
</s>
<s>
Even	O
if	O
the	O
dispersion	O
value	O
of	O
the	O
optical	B-Architecture
fiber	I-Architecture
with	O
the	O
changes	O
of	O
the	O
wavelength	O
is	O
minimum	O
,	O
the	O
dispersion	O
of	O
fiber	O
still	O
needs	O
to	O
be	O
solved	O
.	O
</s>
<s>
For	O
local	B-General_Concept
area	I-General_Concept
networks	I-General_Concept
,	O
since	O
the	O
transmission	O
distance	O
is	O
relatively	O
short	O
,	O
the	O
focus	O
of	O
consideration	O
is	O
on	O
the	O
cost	O
of	O
the	O
optical	O
network	O
rather	O
than	O
the	O
cost	O
of	O
transmission	O
.	O
</s>
<s>
In	O
other	O
words	O
,	O
it	O
is	O
necessary	O
to	O
solve	O
the	O
add/drop	O
multiplexing	O
problem	O
of	O
the	O
upper/lower	O
path	O
in	O
the	O
optical	B-Architecture
fiber	I-Architecture
transmission	O
system	O
,	O
and	O
at	O
the	O
same	O
time	O
,	O
the	O
cost	O
of	O
the	O
add/drop	O
wavelength	O
must	O
be	O
minimized	O
.	O
</s>
<s>
The	O
dispersion-shifted	B-Device
fiber	I-Device
(	O
DSF	O
)	O
and	O
non-zero	B-Architecture
dispersion-shifted	I-Architecture
fiber	I-Architecture
(	O
NZDSF	O
)	O
use	O
technical	O
means	O
to	O
deliberately	O
design	O
the	O
refractive	O
index	O
profile	O
of	O
the	O
fiber	O
to	O
produce	O
waveguide	O
dispersion	O
compared	O
with	O
the	O
material	O
dispersion	O
,	O
so	O
that	O
the	O
zero-dispersion	O
wavelength	O
of	O
DSF	O
moved	O
to	O
around	O
1550nm	O
after	O
the	O
material	O
dispersion	O
and	O
the	O
waveguide	O
dispersion	O
are	O
added	O
.	O
</s>
<s>
In	O
the	O
submarine	O
optical	O
cable	O
transmission	O
system	O
,	O
two	O
kinds	O
of	O
optical	B-Architecture
fibers	I-Architecture
with	O
positive	O
and	O
negative	O
dispersion	O
are	O
combined	O
to	O
form	O
a	O
transmission	O
system	O
for	O
dispersion	O
management	O
.	O
</s>
<s>
With	O
the	O
increase	O
in	O
the	O
distance	O
and	O
capacity	O
of	O
the	O
transmission	O
system	O
,	O
a	O
large	O
number	O
of	O
wavelength	B-Architecture
division	I-Architecture
multiplexing	I-Architecture
(	O
WDM	O
)	O
and	O
dense	B-Architecture
wavelength	I-Architecture
division	I-Architecture
multiplexing	I-Architecture
(	O
DWDM	O
)	O
systems	O
have	O
been	O
put	O
into	O
use	O
.	O
</s>
<s>
In	O
these	O
systems	O
,	O
in	O
order	O
to	O
perform	O
dispersion	O
compensation	O
,	O
a	O
double-clad	O
and	O
triple-clad	O
DCF	O
with	O
refractive	O
index	O
distribution	O
that	O
can	O
work	O
in	O
the	O
C-band	B-Algorithm
and	O
L-band	B-Algorithm
has	O
been	O
developed	O
.	O
</s>
<s>
Amplification	O
fibers	O
,	O
such	O
as	O
erbium-doped	O
fiber	O
(	O
EDF	O
)	O
,	O
thulium-doped	O
fiber	O
(	O
TOF	O
)	O
,	O
etc	O
,	O
can	O
be	O
made	O
by	O
doping	O
rare	O
earth	O
elements	O
,	O
in	O
the	O
core	B-Device
layer	O
of	O
silica	O
fiber	O
.	O
</s>
<s>
Polarization-maintaining	B-Device
fiber	I-Device
is	O
initially	O
developed	O
for	O
coherent	O
optical	O
transmission	O
and	O
later	O
has	O
been	O
used	O
in	O
the	O
technical	O
fields	O
of	O
fiber	B-Architecture
optic	I-Architecture
sensors	O
such	O
as	O
fiber	B-Architecture
optic	I-Architecture
gyroscopes	O
.	O
</s>
<s>
In	O
recent	O
years	O
,	O
due	O
to	O
the	O
increase	O
in	O
the	O
number	O
of	O
wavelength	B-Architecture
division	I-Architecture
multiplexing	I-Architecture
in	O
the	O
DWDM	O
transmission	O
system	O
and	O
the	O
development	O
of	O
high	O
speed	O
,	O
the	O
polarization	B-Device
maintaining	I-Device
fiber	I-Device
has	O
been	O
more	O
widely	O
used	O
.	O
</s>
<s>
Currently	O
,	O
the	O
most	O
widely	O
used	O
fiber	O
is	O
Panda	O
Optical	B-Architecture
Fiber	I-Architecture
(	O
PANDA	O
)	O
.	O
</s>
<s>
PANDA	O
fiber	O
is	O
currently	O
used	O
as	O
pigtails	O
connected	O
with	O
other	O
fiber	B-Architecture
optic	I-Architecture
devices	O
and	O
used	O
in	O
the	O
system	O
as	O
a	O
whole	O
.	O
</s>
<s>
Single-mode	O
non-stripping	O
optical	O
fiber(SM-NSF )	O
is	O
a	O
new	O
type	O
of	O
optical	B-Architecture
fiber	I-Architecture
that	O
still	O
has	O
the	O
NSP	O
polyester	O
layer	O
remaining	O
on	O
the	O
surface	O
of	O
the	O
fiber	O
cladding	B-Device
even	O
after	O
removing	O
the	O
fiber	O
cladding	B-Device
to	O
protect	O
the	O
mechanical	O
properties	O
and	O
high	O
reliability	O
of	O
the	O
optical	B-Architecture
fiber	I-Architecture
.	O
</s>
<s>
It	O
can	O
be	O
widely	O
used	O
in	O
the	O
optical	B-Architecture
fiber	I-Architecture
of	O
the	O
transmission	O
system	O
and	O
is	O
an	O
ideal	O
new-type	O
distribution	O
optical	B-Architecture
fiber	I-Architecture
.	O
</s>
<s>
One	O
of	O
the	O
current	O
research	O
topics	O
of	O
solid-state	O
lasers	O
and	O
gas	O
lasers	O
is	O
laser	O
oscillation	O
technology	O
in	O
the	O
deep	B-Application
ultraviolet	I-Application
field	O
(	O
250nm	O
)	O
.	O
</s>
<s>
Deep	B-Application
ultraviolet	I-Application
light	O
has	O
been	O
extremely	O
widely	O
used	O
in	O
the	O
surface	O
treatment	O
of	O
semiconductor	O
substrates	O
,	O
DNA	O
analysis	O
and	O
testing	O
in	O
the	O
biochemistry	O
field	O
,	O
and	O
the	O
treatment	O
of	O
myopia	O
in	O
the	O
medical	O
field	O
.	O
</s>
