<s>
Holography	B-Algorithm
is	O
a	O
technique	O
that	O
enables	O
a	O
wavefront	O
to	O
be	O
recorded	O
and	O
later	O
re-constructed	O
.	O
</s>
<s>
Holography	B-Algorithm
is	O
best	O
known	O
as	O
a	O
method	O
of	O
generating	O
real	O
three-dimensional	O
images	O
,	O
but	O
it	O
also	O
has	O
a	O
wide	O
range	O
of	O
other	O
applications	O
.	O
</s>
<s>
In	O
principle	O
,	O
it	O
is	O
possible	O
to	O
make	O
a	O
hologram	B-Algorithm
for	O
any	O
type	O
of	O
wave	O
.	O
</s>
<s>
A	O
hologram	B-Algorithm
is	O
made	O
by	O
superimposing	O
a	O
second	O
wavefront	O
(	O
normally	O
called	O
the	O
reference	B-Algorithm
beam	I-Algorithm
)	O
on	O
the	O
wavefront	O
of	O
interest	O
,	O
thereby	O
generating	O
an	O
interference	O
pattern	O
which	O
is	O
recorded	O
on	O
a	O
physical	O
medium	O
.	O
</s>
<s>
Holograms	B-Algorithm
can	O
also	O
be	O
computer-generated	B-Algorithm
by	O
modelling	O
the	O
two	O
wavefronts	O
and	O
adding	O
them	O
together	O
digitally	O
.	O
</s>
<s>
The	O
Hungarian-British	O
physicist	O
Dennis	O
Gabor	O
(	O
in	O
Hungarian	O
:	O
Gábor	O
Dénes	O
)	O
was	O
awarded	O
the	O
Nobel	O
Prize	O
in	O
Physics	O
in	O
1971	O
"	O
for	O
his	O
invention	O
and	O
development	O
of	O
the	O
holographic	B-Algorithm
method	O
"	O
.	O
</s>
<s>
His	O
work	O
,	O
done	O
in	O
the	O
late	O
1940s	O
,	O
was	O
built	O
on	O
pioneering	O
work	O
in	O
the	O
field	O
of	O
X-ray	B-Library
microscopy	O
by	O
other	O
scientists	O
including	O
Mieczysław	O
Wolfke	O
in	O
1920	O
and	O
William	O
Lawrence	O
Bragg	O
in	O
1939	O
.	O
</s>
<s>
The	O
technique	O
as	O
originally	O
invented	O
is	O
still	O
used	O
in	O
electron	O
microscopy	O
,	O
where	O
it	O
is	O
known	O
as	O
electron	B-Algorithm
holography	I-Algorithm
,	O
but	O
optical	O
holography	B-Algorithm
did	O
not	O
really	O
advance	O
until	O
the	O
development	O
of	O
the	O
laser	O
in	O
1960	O
.	O
</s>
<s>
The	O
word	O
holography	B-Algorithm
comes	O
from	O
the	O
Greek	O
words	O
(	O
holos	O
;	O
"	O
whole	O
"	O
)	O
and	O
(	O
graphē	O
;	O
"	O
writing	O
"	O
or	O
"	O
drawing	O
"	O
)	O
.	O
</s>
<s>
A	O
hologram	B-Algorithm
is	O
a	O
recording	O
of	O
an	O
interference	O
pattern	O
which	O
can	O
reproduce	O
a	O
3D	O
light	O
field	O
using	O
diffraction	O
.	O
</s>
<s>
The	O
reproduced	O
light	O
field	O
can	O
generate	O
an	O
image	O
which	O
still	O
has	O
the	O
depth	O
,	O
parallax	B-Device
,	O
and	O
other	O
properties	O
of	O
the	O
original	O
scene	O
.	O
</s>
<s>
A	O
hologram	B-Algorithm
is	O
a	O
photographic	O
recording	O
of	O
a	O
light	O
field	O
,	O
rather	O
than	O
an	O
image	O
formed	O
by	O
a	O
lens	O
.	O
</s>
<s>
The	O
holographic	B-Algorithm
medium	O
,	O
for	O
example	O
the	O
object	O
produced	O
by	O
a	O
holographic	B-Algorithm
process	O
(	O
which	O
may	O
be	O
referred	O
to	O
as	O
a	O
hologram	B-Algorithm
)	O
is	O
usually	O
unintelligible	O
when	O
viewed	O
under	O
diffuse	O
ambient	O
light	O
.	O
</s>
<s>
It	O
is	O
an	O
encoding	B-Algorithm
of	O
the	O
light	O
field	O
as	O
an	O
interference	O
pattern	O
of	O
variations	O
in	O
the	O
opacity	O
,	O
density	O
,	O
or	O
surface	O
profile	O
of	O
the	O
photographic	O
medium	O
.	O
</s>
<s>
When	O
suitably	O
lit	O
,	O
the	O
interference	O
pattern	O
diffracts	O
the	O
light	O
into	O
an	O
accurate	O
reproduction	O
of	O
the	O
original	O
light	O
field	O
,	O
and	O
the	O
objects	O
that	O
were	O
in	O
it	O
exhibit	O
visual	O
depth	O
cues	O
such	O
as	O
parallax	B-Device
and	O
perspective	B-Architecture
that	O
change	O
realistically	O
with	O
the	O
different	O
angles	O
of	O
viewing	O
.	O
</s>
<s>
In	O
this	O
sense	O
,	O
holograms	B-Algorithm
do	O
not	O
have	O
just	O
the	O
illusion	O
of	O
depth	O
but	O
are	O
truly	O
three-dimensional	O
images	O
.	O
</s>
<s>
The	O
development	O
of	O
the	O
laser	O
enabled	O
the	O
first	O
practical	O
optical	O
holograms	B-Algorithm
that	O
recorded	O
3D	O
objects	O
to	O
be	O
made	O
in	O
1962	O
by	O
Yuri	O
Denisyuk	O
in	O
the	O
Soviet	O
Union	O
and	O
by	O
Emmett	B-Algorithm
Leith	I-Algorithm
and	O
Juris	O
Upatnieks	O
at	O
the	O
University	O
of	O
Michigan	O
,	O
US	O
.	O
</s>
<s>
Early	O
holograms	B-Algorithm
used	O
silver	O
halide	O
photographic	O
emulsions	O
as	O
the	O
recording	O
medium	O
.	O
</s>
<s>
Various	O
methods	O
of	O
converting	O
the	O
variation	O
in	O
transmission	O
to	O
a	O
variation	O
in	O
refractive	O
index	O
(	O
known	O
as	O
"	O
bleaching	O
"	O
)	O
were	O
developed	O
which	O
enabled	O
much	O
more	O
efficient	O
holograms	B-Algorithm
to	O
be	O
produced	O
.	O
</s>
<s>
Optical	O
holography	B-Algorithm
needs	O
a	O
laser	O
light	O
to	O
record	O
the	O
light	O
field	O
.	O
</s>
<s>
In	O
its	O
early	O
days	O
,	O
holography	B-Algorithm
required	O
high-power	O
and	O
expensive	O
lasers	O
,	O
but	O
currently	O
,	O
mass-produced	O
low-cost	O
laser	O
diodes	O
,	O
such	O
as	O
those	O
found	O
on	O
DVD	O
recorders	O
and	O
used	O
in	O
other	O
common	O
applications	O
,	O
can	O
be	O
used	O
to	O
make	O
holograms	B-Algorithm
and	O
have	O
made	O
holography	B-Algorithm
much	O
more	O
accessible	O
to	O
low-budget	O
researchers	O
,	O
artists	O
and	O
dedicated	O
hobbyists	O
.	O
</s>
<s>
In	O
common	O
practice	O
,	O
however	O
,	O
major	O
image	O
quality	O
compromises	O
are	O
made	O
to	O
remove	O
the	O
need	O
for	O
laser	O
illumination	O
to	O
view	O
the	O
hologram	B-Algorithm
,	O
and	O
in	O
some	O
cases	O
,	O
to	O
make	O
it	O
.	O
</s>
<s>
Holographic	B-Algorithm
portraiture	O
often	O
resorts	O
to	O
a	O
non-holographic	O
intermediate	O
imaging	O
procedure	O
,	O
to	O
avoid	O
the	O
dangerous	O
high-powered	O
pulsed	O
lasers	O
which	O
would	O
be	O
needed	O
to	O
optically	O
"	O
freeze	O
"	O
moving	O
subjects	O
as	O
perfectly	O
as	O
the	O
extremely	O
motion-intolerant	O
holographic	B-Algorithm
recording	O
process	O
requires	O
.	O
</s>
<s>
Holograms	B-Algorithm
can	O
now	O
also	O
be	O
entirely	O
computer-generated	B-Algorithm
to	O
show	O
objects	O
or	O
scenes	O
that	O
never	O
existed	O
.	O
</s>
<s>
Most	O
holograms	B-Algorithm
produced	O
are	O
of	O
static	O
objects	O
but	O
systems	O
for	O
displaying	O
changing	O
scenes	O
on	O
a	O
holographic	B-Algorithm
volumetric	B-Algorithm
display	I-Algorithm
are	O
now	O
being	O
developed	O
.	O
</s>
<s>
Holography	B-Algorithm
is	O
also	O
used	O
with	O
many	O
other	O
types	O
of	O
waves	O
.	O
</s>
<s>
Holography	B-Algorithm
is	O
a	O
technique	O
that	O
enables	O
a	O
light	O
field	O
(	O
which	O
is	O
generally	O
the	O
result	O
of	O
a	O
light	O
source	O
scattered	O
off	O
objects	O
)	O
to	O
be	O
recorded	O
and	O
later	O
reconstructed	O
when	O
the	O
original	O
light	O
field	O
is	O
no	O
longer	O
present	O
,	O
due	O
to	O
the	O
absence	O
of	O
the	O
original	O
objects	O
.	O
</s>
<s>
Holography	B-Algorithm
can	O
be	O
thought	O
of	O
as	O
somewhat	O
similar	O
to	O
sound	O
recording	O
,	O
whereby	O
a	O
sound	O
field	O
created	O
by	O
vibrating	O
matter	O
like	O
musical	O
instruments	O
or	O
vocal	O
cords	O
,	O
is	O
encoded	B-Algorithm
in	O
such	O
a	O
way	O
that	O
it	O
can	O
be	O
reproduced	O
later	O
,	O
without	O
the	O
presence	O
of	O
the	O
original	O
vibrating	O
matter	O
.	O
</s>
<s>
In	O
laser	O
holography	B-Algorithm
,	O
the	O
hologram	B-Algorithm
is	O
recorded	O
using	O
a	O
source	O
of	O
laser	O
light	O
,	O
which	O
is	O
very	O
pure	O
in	O
its	O
color	O
and	O
orderly	O
in	O
its	O
composition	O
.	O
</s>
<s>
Various	O
setups	O
may	O
be	O
used	O
,	O
and	O
several	O
types	O
of	O
holograms	B-Algorithm
can	O
be	O
made	O
,	O
but	O
all	O
involve	O
the	O
interaction	O
of	O
light	O
coming	O
from	O
different	O
directions	O
and	O
producing	O
a	O
microscopic	O
interference	O
pattern	O
which	O
a	O
plate	B-Algorithm
,	O
film	O
,	O
or	O
other	O
medium	O
photographically	O
records	O
.	O
</s>
<s>
In	O
one	O
common	O
arrangement	O
,	O
the	O
laser	O
beam	O
is	O
split	O
into	O
two	O
,	O
one	O
known	O
as	O
the	O
object	O
beam	O
and	O
the	O
other	O
as	O
the	O
reference	B-Algorithm
beam	I-Algorithm
.	O
</s>
<s>
The	O
reference	B-Algorithm
beam	I-Algorithm
is	O
expanded	O
and	O
made	O
to	O
shine	O
directly	O
on	O
the	O
medium	O
,	O
where	O
it	O
interacts	O
with	O
the	O
light	O
coming	O
from	O
the	O
subject	O
to	O
create	O
the	O
desired	O
interference	O
pattern	O
.	O
</s>
<s>
Like	O
conventional	O
photography	O
,	O
holography	B-Algorithm
requires	O
an	O
appropriate	O
exposure	O
time	O
to	O
correctly	O
affect	O
the	O
recording	O
medium	O
.	O
</s>
<s>
Unlike	O
conventional	O
photography	O
,	O
during	O
the	O
exposure	O
the	O
light	O
source	O
,	O
the	O
optical	O
elements	O
,	O
the	O
recording	O
medium	O
,	O
and	O
the	O
subject	O
must	O
all	O
remain	O
motionless	O
relative	O
to	O
each	O
other	O
,	O
to	O
within	O
about	O
a	O
quarter	O
of	O
the	O
wavelength	O
of	O
the	O
light	O
,	O
or	O
the	O
interference	O
pattern	O
will	O
be	O
blurred	O
and	O
the	O
hologram	B-Algorithm
spoiled	O
.	O
</s>
<s>
A	O
hologram	B-Algorithm
can	O
be	O
made	O
by	O
shining	O
part	O
of	O
the	O
light	O
beam	O
directly	O
into	O
the	O
recording	O
medium	O
,	O
and	O
the	O
other	O
part	O
onto	O
the	O
object	O
in	O
such	O
a	O
way	O
that	O
some	O
of	O
the	O
scattered	O
light	O
falls	O
onto	O
the	O
recording	O
medium	O
.	O
</s>
<s>
A	O
more	O
flexible	O
arrangement	O
for	O
recording	O
a	O
hologram	B-Algorithm
requires	O
the	O
laser	O
beam	O
to	O
be	O
aimed	O
through	O
a	O
series	O
of	O
elements	O
that	O
change	O
it	O
in	O
different	O
ways	O
.	O
</s>
<s>
The	O
second	O
beam	O
(	O
known	O
as	O
the	O
'	O
reference	B-Algorithm
beam	I-Algorithm
 '	O
)	O
is	O
also	O
spread	O
through	O
the	O
use	O
of	O
lenses	O
,	O
but	O
is	O
directed	O
so	O
that	O
it	O
does	O
not	O
come	O
in	O
contact	O
with	O
the	O
scene	O
,	O
and	O
instead	O
travels	O
directly	O
onto	O
the	O
recording	O
medium	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
common	O
is	O
a	O
film	O
very	O
similar	O
to	O
photographic	O
film	O
(	O
silver	O
halide	O
photographic	O
emulsion	O
)	O
,	O
but	O
with	O
much	O
smaller	O
light-reactive	O
grains	O
(	O
preferably	O
with	O
diameters	O
less	O
than	O
20	O
nm	O
)	O
,	O
making	O
it	O
capable	O
of	O
the	O
much	O
higher	O
resolution	O
that	O
holograms	B-Algorithm
require	O
.	O
</s>
<s>
The	O
interference	O
pattern	O
can	O
be	O
considered	O
an	O
encoded	B-Algorithm
version	O
of	O
the	O
scene	O
,	O
requiring	O
a	O
particular	O
key	O
–	O
the	O
original	O
light	O
source	O
–	O
in	O
order	O
to	O
view	O
its	O
contents	O
.	O
</s>
<s>
This	O
missing	O
key	O
is	O
provided	O
later	O
by	O
shining	O
a	O
laser	O
,	O
identical	O
to	O
the	O
one	O
used	O
to	O
record	O
the	O
hologram	B-Algorithm
,	O
onto	O
the	O
developed	O
film	O
.	O
</s>
<s>
When	O
this	O
beam	O
illuminates	O
the	O
hologram	B-Algorithm
,	O
it	O
is	O
diffracted	O
by	O
the	O
hologram	B-Algorithm
's	O
surface	O
pattern	O
.	O
</s>
<s>
This	O
produces	O
a	O
light	O
field	O
identical	O
to	O
the	O
one	O
originally	O
produced	O
by	O
the	O
scene	O
and	O
scattered	O
onto	O
the	O
hologram	B-Algorithm
.	O
</s>
<s>
Holography	B-Algorithm
may	O
be	O
better	O
understood	O
via	O
an	O
examination	O
of	O
its	O
differences	O
from	O
ordinary	O
photography	O
:	O
</s>
<s>
A	O
hologram	B-Algorithm
represents	O
a	O
recording	O
of	O
information	O
regarding	O
the	O
light	O
that	O
came	O
from	O
the	O
original	O
scene	O
as	O
scattered	O
in	O
a	O
range	O
of	O
directions	O
rather	O
than	O
from	O
only	O
one	O
direction	O
,	O
as	O
in	O
a	O
photograph	O
.	O
</s>
<s>
A	O
photograph	O
can	O
be	O
recorded	O
using	O
normal	O
light	O
sources	O
(	O
sunlight	O
or	O
electric	O
lighting	O
)	O
whereas	O
a	O
laser	O
is	O
required	O
to	O
record	O
a	O
hologram	B-Algorithm
.	O
</s>
<s>
A	O
lens	O
is	O
required	O
in	O
photography	O
to	O
record	O
the	O
image	O
,	O
whereas	O
in	O
holography	B-Algorithm
,	O
the	O
light	O
from	O
the	O
object	O
is	O
scattered	O
directly	O
onto	O
the	O
recording	O
medium	O
.	O
</s>
<s>
A	O
holographic	B-Algorithm
recording	O
requires	O
a	O
second	O
light	O
beam	O
(	O
the	O
reference	B-Algorithm
beam	I-Algorithm
)	O
to	O
be	O
directed	O
onto	O
the	O
recording	O
medium	O
.	O
</s>
<s>
A	O
photograph	O
can	O
be	O
viewed	O
in	O
a	O
wide	O
range	O
of	O
lighting	O
conditions	O
,	O
whereas	O
holograms	B-Algorithm
can	O
only	O
be	O
viewed	O
with	O
very	O
specific	O
forms	O
of	O
illumination	O
.	O
</s>
<s>
When	O
a	O
hologram	B-Algorithm
is	O
cut	O
in	O
half	O
,	O
the	O
whole	O
scene	O
can	O
still	O
be	O
seen	O
in	O
each	O
piece	O
.	O
</s>
<s>
This	O
is	O
because	O
,	O
whereas	O
each	O
point	O
in	O
a	O
photograph	O
only	O
represents	O
light	O
scattered	O
from	O
a	O
single	O
point	O
in	O
the	O
scene	O
,	O
each	O
point	O
on	O
a	O
holographic	B-Algorithm
recording	O
includes	O
information	O
about	O
light	O
scattered	O
from	O
every	O
point	O
in	O
the	O
scene	O
.	O
</s>
<s>
A	O
photograph	O
is	O
a	O
two-dimensional	O
representation	O
that	O
can	O
only	O
reproduce	O
a	O
rudimentary	O
three-dimensional	O
effect	O
,	O
whereas	O
the	O
reproduced	O
viewing	O
range	O
of	O
a	O
hologram	B-Algorithm
adds	O
many	O
more	O
depth	O
perception	O
cues	O
that	O
were	O
present	O
in	O
the	O
original	O
scene	O
.	O
</s>
<s>
The	O
developed	O
hologram	B-Algorithm
's	O
surface	O
consists	O
of	O
a	O
very	O
fine	O
,	O
seemingly	O
random	O
pattern	O
,	O
which	O
appears	O
to	O
bear	O
no	O
relationship	O
to	O
the	O
scene	O
it	O
recorded	O
.	O
</s>
<s>
The	O
process	O
of	O
producing	O
a	O
holographic	B-Algorithm
reconstruction	O
is	O
explained	O
below	O
purely	O
in	O
terms	O
of	O
interference	O
and	O
diffraction	O
.	O
</s>
<s>
It	O
is	O
somewhat	O
simplified	O
but	O
is	O
accurate	O
enough	O
to	O
give	O
an	O
understanding	O
of	O
how	O
the	O
holographic	B-Algorithm
process	O
works	O
.	O
</s>
<s>
A	O
simple	O
example	O
is	O
a	O
metal	O
plate	B-Algorithm
with	O
slits	O
cut	O
at	O
regular	O
intervals	O
.	O
</s>
<s>
A	O
simple	O
hologram	B-Algorithm
can	O
be	O
made	O
by	O
superimposing	O
two	O
plane	O
waves	O
from	O
the	O
same	O
light	O
source	O
on	O
a	O
holographic	B-Algorithm
recording	O
medium	O
.	O
</s>
<s>
Thus	O
,	O
the	O
recorded	O
light	O
pattern	O
is	O
a	O
holographic	B-Algorithm
recording	O
as	O
defined	O
above	O
.	O
</s>
<s>
If	O
the	O
recording	O
medium	O
is	O
illuminated	O
with	O
a	O
point	O
source	O
and	O
a	O
normally	O
incident	O
plane	O
wave	O
,	O
the	O
resulting	O
pattern	O
is	O
a	O
sinusoidal	O
zone	O
plate	B-Algorithm
,	O
which	O
acts	O
as	O
a	O
negative	O
Fresnel	O
lens	O
whose	O
focal	O
length	O
is	O
equal	O
to	O
the	O
separation	O
of	O
the	O
point	O
source	O
and	O
the	O
recording	O
plane	O
.	O
</s>
<s>
Thus	O
,	O
when	O
the	O
recorded	O
pattern	O
is	O
illuminated	O
with	O
the	O
original	O
plane	O
wave	O
,	O
some	O
of	O
the	O
light	O
is	O
diffracted	O
into	O
a	O
diverging	O
beam	O
equivalent	O
to	O
the	O
original	O
spherical	O
wave	O
;	O
a	O
holographic	B-Algorithm
recording	O
of	O
the	O
point	O
source	O
has	O
been	O
created	O
.	O
</s>
<s>
To	O
record	O
a	O
hologram	B-Algorithm
of	O
a	O
complex	O
object	O
,	O
a	O
laser	O
beam	O
is	O
first	O
split	O
into	O
two	O
beams	O
of	O
light	O
.	O
</s>
<s>
Each	O
point	O
source	O
wave	O
interferes	O
with	O
the	O
reference	B-Algorithm
beam	I-Algorithm
,	O
giving	O
rise	O
to	O
its	O
own	O
sinusoidal	O
zone	O
plate	B-Algorithm
in	O
the	O
recording	O
medium	O
.	O
</s>
<s>
The	O
resulting	O
pattern	O
is	O
the	O
sum	O
of	O
all	O
these	O
'	O
zone	O
plates	B-Algorithm
 '	O
,	O
which	O
combine	O
to	O
produce	O
a	O
random	O
(	O
speckle	O
)	O
pattern	O
as	O
in	O
the	O
photograph	O
above	O
.	O
</s>
<s>
When	O
the	O
hologram	B-Algorithm
is	O
illuminated	O
by	O
the	O
original	O
reference	B-Algorithm
beam	I-Algorithm
,	O
each	O
of	O
the	O
individual	O
zone	O
plates	B-Algorithm
reconstructs	O
the	O
object	O
wave	O
that	O
produced	O
it	O
,	O
and	O
these	O
individual	O
wavefronts	O
are	O
combined	O
to	O
reconstruct	O
the	O
whole	O
of	O
the	O
object	O
beam	O
.	O
</s>
<s>
Early	O
on	O
,	O
artists	O
saw	O
the	O
potential	O
of	O
holography	B-Algorithm
as	O
a	O
medium	O
and	O
gained	O
access	O
to	O
science	O
laboratories	O
to	O
create	O
their	O
work	O
.	O
</s>
<s>
Holographic	B-Algorithm
art	I-Algorithm
is	O
often	O
the	O
result	O
of	O
collaborations	O
between	O
scientists	O
and	O
artists	O
,	O
although	O
some	O
holographers	O
would	O
regard	O
themselves	O
as	O
both	O
an	O
artist	O
and	O
a	O
scientist	O
.	O
</s>
<s>
Salvador	O
Dalí	O
claimed	O
to	O
have	O
been	O
the	O
first	O
to	O
employ	O
holography	B-Algorithm
artistically	O
.	O
</s>
<s>
He	O
was	O
certainly	O
the	O
first	O
and	O
best-known	O
surrealist	O
to	O
do	O
so	O
,	O
but	O
the	O
1972	O
New	O
York	O
exhibit	O
of	O
Dalí	O
holograms	B-Algorithm
had	O
been	O
preceded	O
by	O
the	O
holographic	B-Algorithm
art	I-Algorithm
exhibition	O
that	O
was	O
held	O
at	O
the	O
Cranbrook	O
Academy	O
of	O
Art	O
in	O
Michigan	O
in	O
1968	O
and	O
by	O
the	O
one	O
at	O
the	O
Finch	O
College	O
gallery	O
in	O
New	O
York	O
in	O
1970	O
,	O
which	O
attracted	O
national	O
media	O
attention	O
.	O
</s>
<s>
In	O
Great	O
Britain	O
,	O
Margaret	O
Benyon	O
began	O
using	O
holography	B-Algorithm
as	O
an	O
artistic	O
medium	O
in	O
the	O
late	O
1960s	O
and	O
had	O
a	O
solo	O
exhibition	O
at	O
the	O
University	O
of	O
Nottingham	O
art	O
gallery	O
in	O
1969	O
.	O
</s>
<s>
This	O
was	O
followed	O
in	O
1970	O
by	O
a	O
solo	O
show	O
at	O
the	O
Lisson	O
Gallery	O
in	O
London	O
,	O
which	O
was	O
billed	O
as	O
the	O
"	O
first	O
London	O
expo	O
of	O
holograms	B-Algorithm
and	O
stereoscopic	O
paintings	O
"	O
.	O
</s>
<s>
During	O
the	O
1970s	O
,	O
a	O
number	O
of	O
art	O
studios	O
and	O
schools	O
were	O
established	O
,	O
each	O
with	O
their	O
particular	O
approach	O
to	O
holography	B-Algorithm
.	O
</s>
<s>
Notably	O
,	O
there	O
was	O
the	O
San	O
Francisco	O
School	O
of	O
Holography	B-Algorithm
established	O
by	O
Lloyd	O
Cross	O
,	O
The	O
Museum	O
of	O
Holography	B-Algorithm
in	O
New	O
York	O
founded	O
by	O
Rosemary	O
(	O
Posy	O
)	O
H	O
.	O
Jackson	O
,	O
the	O
Royal	O
College	O
of	O
Art	O
in	O
London	O
and	O
the	O
Lake	O
Forest	O
College	O
Symposiums	O
organised	O
by	O
Tung	O
Jeong	O
.	O
</s>
<s>
None	O
of	O
these	O
studios	O
still	O
exist	O
;	O
however	O
,	O
there	O
is	O
the	O
Center	O
for	O
the	O
Holographic	B-Algorithm
Arts	I-Algorithm
in	O
New	O
York	O
and	O
the	O
HOLOcenter	O
in	O
Seoul	O
,	O
which	O
offers	O
artists	O
a	O
place	O
to	O
create	O
and	O
exhibit	O
work	O
.	O
</s>
<s>
During	O
the	O
1980s	O
,	O
many	O
artists	O
who	O
worked	O
with	O
holography	B-Algorithm
helped	O
the	O
diffusion	O
of	O
this	O
so-called	O
"	O
new	O
medium	O
"	O
in	O
the	O
art	O
world	O
,	O
such	O
as	O
Harriet	O
Casdin-Silver	O
of	O
the	O
United	O
States	O
,	O
Dieter	O
Jung	O
of	O
Germany	O
,	O
and	O
Moysés	O
Baumstein	O
of	O
Brazil	O
,	O
each	O
one	O
searching	O
for	O
a	O
proper	O
"	O
language	O
"	O
to	O
use	O
with	O
the	O
three-dimensional	O
work	O
,	O
avoiding	O
the	O
simple	O
holographic	B-Algorithm
reproduction	O
of	O
a	O
sculpture	O
or	O
object	O
.	O
</s>
<s>
For	O
instance	O
,	O
in	O
Brazil	O
,	O
many	O
concrete	O
poets	O
(	O
Augusto	O
de	O
Campos	O
,	O
Décio	O
Pignatari	O
,	O
Julio	O
Plaza	O
and	O
José	O
Wagner	O
Garcia	O
,	O
associated	O
with	O
Moysés	O
Baumstein	O
)	O
found	O
in	O
holography	B-Algorithm
a	O
way	O
to	O
express	O
themselves	O
and	O
to	O
renew	O
Concrete	O
Poetry	O
.	O
</s>
<s>
A	O
small	O
but	O
active	O
group	O
of	O
artists	O
still	O
integrate	O
holographic	B-Algorithm
elements	O
into	O
their	O
work	O
.	O
</s>
<s>
Some	O
are	O
associated	O
with	O
novel	O
holographic	B-Algorithm
techniques	O
;	O
for	O
example	O
,	O
artist	O
Matt	O
Brand	O
employed	O
computational	O
mirror	O
design	O
to	O
eliminate	O
image	O
distortion	O
from	O
specular	B-Algorithm
holography	I-Algorithm
.	O
</s>
<s>
The	O
MIT	O
Museum	O
and	O
Jonathan	O
Ross	O
both	O
have	O
extensive	O
collections	O
of	O
holography	B-Algorithm
and	O
on-line	O
catalogues	O
of	O
art	O
holograms	B-Algorithm
.	O
</s>
<s>
Holographic	B-Algorithm
data	I-Algorithm
storage	I-Algorithm
is	O
a	O
technique	O
that	O
can	O
store	O
information	O
at	O
high	O
density	O
inside	O
crystals	O
or	O
photopolymers	O
.	O
</s>
<s>
As	O
current	O
storage	O
techniques	O
such	O
as	O
Blu-ray	O
Disc	O
reach	O
the	O
limit	O
of	O
possible	O
data	O
density	O
(	O
due	O
to	O
the	O
diffraction-limited	O
size	O
of	O
the	O
writing	B-Algorithm
beams	I-Algorithm
)	O
,	O
holographic	B-Algorithm
storage	I-Algorithm
has	O
the	O
potential	O
to	O
become	O
the	O
next	O
generation	O
of	O
popular	O
storage	O
media	O
.	O
</s>
<s>
In	O
2005	O
,	O
companies	O
such	O
as	O
Optware	O
and	O
Maxell	O
produced	O
a	O
120mm	O
disc	O
that	O
uses	O
a	O
holographic	B-Algorithm
layer	O
to	O
store	O
data	O
to	O
a	O
potential	O
3.9TB	O
,	O
a	O
format	O
called	O
Holographic	B-Device
Versatile	I-Device
Disc	I-Device
.	O
</s>
<s>
Another	O
company	O
,	O
InPhase	B-Algorithm
Technologies	I-Algorithm
,	O
was	O
developing	O
a	O
competing	O
format	O
,	O
but	O
went	O
bankrupt	O
in	O
2011	O
and	O
all	O
its	O
assets	O
were	O
sold	O
to	O
Akonia	B-Algorithm
Holographics	I-Algorithm
,	O
LLC	O
.	O
</s>
<s>
While	O
many	O
holographic	B-Algorithm
data	I-Algorithm
storage	I-Algorithm
models	O
have	O
used	O
"	O
page-based	O
"	O
storage	O
,	O
where	O
each	O
recorded	O
hologram	B-Algorithm
holds	O
a	O
large	O
amount	O
of	O
data	O
,	O
more	O
recent	O
research	O
into	O
using	O
submicrometre-sized	O
"	O
microholograms	O
"	O
has	O
resulted	O
in	O
several	O
potential	O
3D	O
optical	O
data	O
storage	O
solutions	O
.	O
</s>
<s>
In	O
static	O
holography	B-Algorithm
,	O
recording	O
,	O
developing	O
and	O
reconstructing	O
occur	O
sequentially	O
,	O
and	O
a	O
permanent	O
hologram	B-Algorithm
is	O
produced	O
.	O
</s>
<s>
There	O
also	O
exist	O
holographic	B-Algorithm
materials	O
that	O
do	O
not	O
need	O
the	O
developing	O
process	O
and	O
can	O
record	O
a	O
hologram	B-Algorithm
in	O
a	O
very	O
short	O
time	O
.	O
</s>
<s>
This	O
allows	O
one	O
to	O
use	O
holography	B-Algorithm
to	O
perform	O
some	O
simple	O
operations	O
in	O
an	O
all-optical	O
way	O
.	O
</s>
<s>
Examples	O
of	O
applications	O
of	O
such	O
real-time	O
holograms	B-Algorithm
include	O
phase-conjugate	O
mirrors	O
(	O
"	O
time-reversal	O
"	O
of	O
light	O
)	O
,	O
optical	O
cache	O
memories	O
,	O
image	B-Algorithm
processing	I-Algorithm
(	O
pattern	O
recognition	O
of	O
time-varying	O
images	O
)	O
,	O
and	O
optical	O
computing	O
.	O
</s>
<s>
The	O
optical	O
processing	O
performed	O
by	O
a	O
dynamic	O
hologram	B-Algorithm
is	O
also	O
much	O
less	O
flexible	O
than	O
electronic	O
processing	O
.	O
</s>
<s>
On	O
one	O
side	O
,	O
one	O
has	O
to	O
perform	O
the	O
operation	O
always	O
on	O
the	O
whole	O
image	O
,	O
and	O
on	O
the	O
other	O
side	O
,	O
the	O
operation	O
a	O
hologram	B-Algorithm
can	O
perform	O
is	O
basically	O
either	O
a	O
multiplication	O
or	O
a	O
phase	O
conjugation	O
.	O
</s>
<s>
In	O
optics	O
,	O
addition	O
and	O
Fourier	B-Algorithm
transform	I-Algorithm
are	O
already	O
easily	O
performed	O
in	O
linear	O
materials	O
,	O
the	O
latter	O
simply	O
by	O
a	O
lens	O
.	O
</s>
<s>
The	O
search	O
for	O
novel	O
nonlinear	O
optical	O
materials	O
for	O
dynamic	O
holography	B-Algorithm
is	O
an	O
active	O
area	O
of	O
research	O
.	O
</s>
<s>
The	O
most	O
common	O
materials	O
are	O
photorefractive	O
crystals	O
,	O
but	O
in	O
semiconductors	O
or	O
semiconductor	O
heterostructures	O
(	O
such	O
as	O
quantum	O
wells	O
)	O
,	O
atomic	O
vapors	O
and	O
gases	O
,	O
plasmas	O
and	O
even	O
liquids	O
,	O
it	O
was	O
possible	O
to	O
generate	O
holograms	B-Algorithm
.	O
</s>
<s>
Since	O
the	O
beginning	O
of	O
holography	B-Algorithm
,	O
amateur	O
experimenters	O
have	O
explored	O
its	O
uses	O
.	O
</s>
<s>
In	O
1971	O
,	O
Lloyd	O
Cross	O
opened	O
the	O
San	O
Francisco	O
School	O
of	O
Holography	B-Algorithm
and	O
taught	O
amateurs	O
how	O
to	O
make	O
holograms	B-Algorithm
using	O
only	O
a	O
small	O
(	O
typically	O
5mW	O
)	O
helium-neon	O
laser	O
and	O
inexpensive	O
home-made	O
equipment	O
.	O
</s>
<s>
Holography	B-Algorithm
had	O
been	O
supposed	O
to	O
require	O
a	O
very	O
expensive	O
metal	O
optical	O
table	O
set-up	O
to	O
lock	O
all	O
the	O
involved	O
elements	O
down	O
in	O
place	O
and	O
damp	O
any	O
vibrations	O
that	O
could	O
blur	O
the	O
interference	O
fringes	O
and	O
ruin	O
the	O
hologram	B-Algorithm
.	O
</s>
<s>
The	O
subject	O
and	O
the	O
photographic	B-Algorithm
plate	I-Algorithm
holder	O
were	O
similarly	O
supported	O
within	O
the	O
sandbox	O
.	O
</s>
<s>
The	O
holographer	O
turned	O
off	O
the	O
room	O
light	O
,	O
blocked	O
the	O
laser	O
beam	O
near	O
its	O
source	O
using	O
a	O
small	O
relay-controlled	O
shutter	O
,	O
loaded	O
a	O
plate	B-Algorithm
into	O
the	O
holder	O
in	O
the	O
dark	O
,	O
left	O
the	O
room	O
,	O
waited	O
a	O
few	O
minutes	O
to	O
let	O
everything	O
settle	O
,	O
then	O
made	O
the	O
exposure	O
by	O
remotely	O
operating	O
the	O
laser	O
shutter	O
.	O
</s>
<s>
Many	O
of	O
these	O
holographers	O
would	O
go	O
on	O
to	O
produce	O
art	O
holograms	B-Algorithm
.	O
</s>
<s>
In	O
1983	O
,	O
Fred	O
Unterseher	O
,	O
a	O
co-founder	O
of	O
the	O
San	O
Francisco	O
School	O
of	O
Holography	B-Algorithm
and	O
a	O
well-known	O
holographic	B-Algorithm
artist	O
,	O
published	O
the	O
Holography	B-Algorithm
Handbook	O
,	O
an	O
easy-to-read	O
guide	O
to	O
making	O
holograms	B-Algorithm
at	O
home	O
.	O
</s>
<s>
In	O
2000	O
,	O
Frank	O
DeFreitas	O
published	O
the	O
Shoebox	O
Holography	B-Algorithm
Book	O
and	O
introduced	O
the	O
use	O
of	O
inexpensive	O
laser	O
pointers	O
to	O
countless	O
hobbyists	O
.	O
</s>
<s>
For	O
many	O
years	O
,	O
it	O
had	O
been	O
assumed	O
that	O
certain	O
characteristics	O
of	O
semiconductor	O
laser	O
diodes	O
made	O
them	O
virtually	O
useless	O
for	O
creating	O
holograms	B-Algorithm
,	O
but	O
when	O
they	O
were	O
eventually	O
put	O
to	O
the	O
test	O
of	O
practical	O
experiment	O
,	O
it	O
was	O
found	O
that	O
not	O
only	O
was	O
this	O
untrue	O
,	O
but	O
that	O
some	O
actually	O
provided	O
a	O
coherence	O
length	O
much	O
greater	O
than	O
that	O
of	O
traditional	O
helium-neon	O
gas	O
lasers	O
.	O
</s>
<s>
By	O
late	O
2000	O
,	O
holography	B-Algorithm
kits	O
with	O
inexpensive	O
laser	O
pointer	O
diodes	O
entered	O
the	O
mainstream	O
consumer	O
market	O
.	O
</s>
<s>
These	O
kits	O
enabled	O
students	O
,	O
teachers	O
,	O
and	O
hobbyists	O
to	O
make	O
several	O
kinds	O
of	O
holograms	B-Algorithm
without	O
specialized	O
equipment	O
,	O
and	O
became	O
popular	O
gift	O
items	O
by	O
2005	O
.	O
</s>
<s>
The	O
introduction	O
of	O
holography	B-Algorithm
kits	O
with	O
self-developing	O
plates	B-Algorithm
in	O
2003	O
made	O
it	O
possible	O
for	O
hobbyists	O
to	O
create	O
holograms	B-Algorithm
without	O
the	O
bother	O
of	O
wet	O
chemical	O
processing	O
.	O
</s>
<s>
In	O
2006	O
,	O
a	O
large	O
number	O
of	O
surplus	O
holography-quality	O
green	O
lasers	O
(	O
Coherent	O
C315	O
)	O
became	O
available	O
and	O
put	O
dichromated	O
gelatin	O
(	O
DCG	O
)	O
holography	B-Algorithm
within	O
the	O
reach	O
of	O
the	O
amateur	O
holographer	O
.	O
</s>
<s>
The	O
holography	B-Algorithm
community	O
was	O
surprised	O
at	O
the	O
amazing	O
sensitivity	O
of	O
DCG	O
to	O
green	O
light	O
.	O
</s>
<s>
Kodak	O
and	O
Agfa	O
,	O
the	O
former	O
major	O
suppliers	O
of	O
holography-quality	O
silver	O
halide	O
plates	B-Algorithm
and	O
films	O
,	O
are	O
no	O
longer	O
in	O
the	O
market	O
.	O
</s>
<s>
A	O
small	O
group	O
of	O
amateurs	O
are	O
even	O
constructing	O
their	O
own	O
pulsed	O
lasers	O
to	O
make	O
holograms	B-Algorithm
of	O
living	O
subjects	O
and	O
other	O
unsteady	O
or	O
moving	O
objects	O
.	O
</s>
<s>
Holographic	B-Algorithm
interferometry	O
(	O
HI	O
)	O
is	O
a	O
technique	O
that	O
enables	O
static	O
and	O
dynamic	O
displacements	O
of	O
objects	O
with	O
optically	O
rough	O
surfaces	O
to	O
be	O
measured	O
to	O
optical	O
interferometric	O
precision	O
(	O
i.e.	O
</s>
<s>
The	O
hologram	B-Algorithm
keeps	O
the	O
information	O
on	O
the	O
amplitude	O
and	O
phase	O
of	O
the	O
field	O
.	O
</s>
<s>
Several	O
holograms	B-Algorithm
may	O
keep	O
information	O
about	O
the	O
same	O
distribution	O
of	O
light	O
,	O
emitted	O
to	O
various	O
directions	O
.	O
</s>
<s>
The	O
numerical	O
analysis	O
of	O
such	O
holograms	B-Algorithm
allows	O
one	O
to	O
emulate	O
large	O
numerical	O
aperture	O
,	O
which	O
,	O
in	O
turn	O
,	O
enables	O
enhancement	O
of	O
the	O
resolution	O
of	O
optical	O
microscopy	O
.	O
</s>
<s>
The	O
hologram	B-Algorithm
is	O
made	O
with	O
a	O
modified	O
material	O
that	O
interacts	O
with	O
certain	O
molecules	O
generating	O
a	O
change	O
in	O
the	O
fringe	O
periodicity	O
or	O
refractive	O
index	O
,	O
therefore	O
,	O
the	O
color	O
of	O
the	O
holographic	B-Algorithm
reflection	O
.	O
</s>
<s>
Holograms	B-Algorithm
are	O
commonly	O
used	O
for	O
security	O
,	O
as	O
they	O
are	O
replicated	O
from	O
a	O
master	O
hologram	B-Algorithm
that	O
requires	O
expensive	O
,	O
specialized	O
and	O
technologically	O
advanced	O
equipment	O
,	O
and	O
are	O
thus	O
difficult	O
to	O
forge	O
.	O
</s>
<s>
They	O
can	O
also	O
be	O
found	O
in	O
credit	O
and	O
bank	O
cards	O
as	O
well	O
as	O
passports	B-Protocol
,	O
ID	O
cards	O
,	O
books	O
,	O
food	O
packaging	O
,	O
DVDs	O
,	O
and	O
sports	O
equipment	O
.	O
</s>
<s>
Such	O
holograms	B-Algorithm
come	O
in	O
a	O
variety	O
of	O
forms	O
,	O
from	O
adhesive	O
strips	O
that	O
are	O
laminated	O
on	O
packaging	O
for	O
fast-moving	O
consumer	O
goods	O
to	O
holographic	B-Algorithm
tags	O
on	O
electronic	O
products	O
.	O
</s>
<s>
Holographic	B-Algorithm
scanners	O
are	O
in	O
use	O
in	O
post	O
offices	O
,	O
larger	O
shipping	O
firms	O
,	O
and	O
automated	O
conveyor	O
systems	O
to	O
determine	O
the	O
three-dimensional	O
size	O
of	O
a	O
package	O
.	O
</s>
<s>
They	O
are	O
often	O
used	O
in	O
tandem	O
with	O
checkweighers	B-Algorithm
to	O
allow	O
automated	O
pre-packing	O
of	O
given	O
volumes	O
,	O
such	O
as	O
a	O
truck	O
or	O
pallet	O
for	O
bulk	O
shipment	O
of	O
goods	O
.	O
</s>
<s>
Holograms	B-Algorithm
produced	O
in	O
elastomers	O
can	O
be	O
used	O
as	O
stress-strain	O
reporters	O
due	O
to	O
its	O
elasticity	O
and	O
compressibility	O
,	O
the	O
pressure	O
and	O
force	O
applied	O
are	O
correlated	O
to	O
the	O
reflected	O
wavelength	O
,	O
therefore	O
its	O
color	O
.	O
</s>
<s>
Holography	B-Algorithm
technique	O
can	O
also	O
be	O
effectively	O
used	O
for	O
radiation	O
dosimetry	O
.	O
</s>
<s>
High-security	O
holograms	B-Algorithm
can	O
be	O
used	O
on	O
license	O
plates	B-Algorithm
for	O
vehicles	O
such	O
as	O
cars	O
and	O
motorcycles	O
.	O
</s>
<s>
As	O
of	O
April	O
2019	O
,	O
holographic	B-Algorithm
license	O
plates	B-Algorithm
are	O
required	O
on	O
vehicles	O
in	O
parts	O
of	O
India	O
to	O
aid	O
in	O
identification	O
and	O
security	O
,	O
especially	O
in	O
cases	O
of	O
car	O
theft	O
.	O
</s>
<s>
Such	O
number	O
plates	B-Algorithm
hold	O
electronic	O
data	O
of	O
vehicles	O
,	O
and	O
have	O
a	O
unique	O
ID	O
number	O
and	O
a	O
sticker	O
to	O
indicate	O
authenticity	O
.	O
</s>
<s>
In	O
principle	O
,	O
it	O
is	O
possible	O
to	O
make	O
a	O
hologram	B-Algorithm
for	O
any	O
wave	O
.	O
</s>
<s>
Electron	B-Algorithm
holography	I-Algorithm
is	O
the	O
application	O
of	O
holography	B-Algorithm
techniques	O
to	O
electron	O
waves	O
rather	O
than	O
light	O
waves	O
.	O
</s>
<s>
Electron	B-Algorithm
holography	I-Algorithm
was	O
invented	O
by	O
Dennis	O
Gabor	O
to	O
improve	O
the	O
resolution	O
and	O
avoid	O
the	O
aberrations	O
of	O
the	O
transmission	O
electron	O
microscope	O
.	O
</s>
<s>
The	O
principle	O
of	O
electron	B-Algorithm
holography	I-Algorithm
can	O
also	O
be	O
applied	O
to	O
interference	B-Algorithm
lithography	I-Algorithm
.	O
</s>
<s>
Acoustic	O
holography	B-Algorithm
enables	O
sound	O
maps	O
of	O
an	O
object	O
to	O
be	O
generated	O
.	O
</s>
<s>
Atomic	O
holography	B-Algorithm
has	O
evolved	O
out	O
of	O
the	O
development	O
of	O
the	O
basic	O
elements	O
of	O
atom	O
optics	O
.	O
</s>
<s>
With	O
the	O
Fresnel	O
diffraction	O
lens	O
and	O
atomic	O
mirrors	O
atomic	O
holography	B-Algorithm
follows	O
a	O
natural	O
step	O
in	O
the	O
development	O
of	O
the	O
physics	O
(	O
and	O
applications	O
)	O
of	O
atomic	O
beams	O
.	O
</s>
<s>
Recent	O
developments	O
including	O
atomic	O
mirrors	O
and	O
especially	O
ridged	O
mirrors	O
have	O
provided	O
the	O
tools	O
necessary	O
for	O
the	O
creation	O
of	O
atomic	O
holograms	B-Algorithm
,	O
although	O
such	O
holograms	B-Algorithm
have	O
not	O
yet	O
been	O
commercialized	O
.	O
</s>
<s>
Neutron	O
beam	O
holography	B-Algorithm
has	O
been	O
used	O
to	O
see	O
the	O
inside	O
of	O
solid	O
objects	O
.	O
</s>
<s>
Holograms	B-Algorithm
with	O
x-rays	B-Library
are	O
generated	O
by	O
using	O
synchrotrons	O
or	O
x-ray	B-Library
free-electron	O
lasers	O
as	O
radiation	O
sources	O
and	O
pixelated	O
detectors	O
such	O
as	O
CCDs	B-Algorithm
as	O
recording	O
medium	O
.	O
</s>
<s>
Due	O
to	O
the	O
shorter	O
wavelength	O
of	O
x-rays	B-Library
compared	O
to	O
visible	O
light	O
,	O
this	O
approach	O
allows	O
imaging	O
objects	O
with	O
higher	O
spatial	O
resolution	O
.	O
</s>
<s>
As	O
free-electron	O
lasers	O
can	O
provide	O
ultrashort	O
and	O
x-ray	B-Library
pulses	O
in	O
the	O
range	O
of	O
femtoseconds	O
which	O
are	O
intense	O
and	O
coherent	O
,	O
x-ray	B-Library
holography	B-Algorithm
has	O
been	O
used	O
to	O
capture	O
ultrafast	O
dynamic	O
processes	O
.	O
</s>
<s>
Effects	O
produced	O
by	O
lenticular	O
printing	O
,	O
the	O
Pepper	O
's	O
ghost	O
illusion	O
(	O
or	O
modern	O
variants	O
such	O
as	O
the	O
Musion	O
Eyeliner	O
)	O
,	O
tomography	B-Algorithm
and	O
volumetric	B-Algorithm
displays	I-Algorithm
are	O
often	O
confused	O
with	O
holograms	B-Algorithm
.	O
</s>
<s>
The	O
Pepper	O
's	O
ghost	O
technique	O
,	O
being	O
the	O
easiest	O
to	O
implement	O
of	O
these	O
methods	O
,	O
is	O
most	O
prevalent	O
in	O
3D	O
displays	O
that	O
claim	O
to	O
be	O
(	O
or	O
are	O
referred	O
to	O
as	O
)	O
"	O
holographic	B-Algorithm
"	O
.	O
</s>
<s>
An	O
even	O
simpler	O
illusion	O
can	O
be	O
created	O
by	O
rear-projecting	B-Device
realistic	O
images	O
into	O
semi-transparent	O
screens	O
.	O
</s>
<s>
Crypton	O
Future	O
Media	O
,	O
a	O
music	O
software	O
company	O
that	O
produced	O
Hatsune	O
Miku	O
,	O
one	O
of	O
many	O
Vocaloid	B-Application
singing	O
synthesizer	O
applications	O
,	O
has	O
produced	O
concerts	O
that	O
have	O
Miku	O
,	O
along	O
with	O
other	O
Crypton	O
Vocaloids	B-Application
,	O
performing	O
on	O
stage	O
as	O
"	O
holographic	B-Algorithm
"	O
characters	O
.	O
</s>
<s>
These	O
concerts	O
use	O
rear	O
projection	O
onto	O
a	O
semi-transparent	O
DILAD	O
screen	O
to	O
achieve	O
its	O
"	O
holographic	B-Algorithm
"	O
effect	O
.	O
</s>
<s>
In	O
2011	O
,	O
in	O
Beijing	O
,	O
apparel	O
company	O
Burberry	O
produced	O
the	O
"	O
Burberry	O
Prorsum	O
Autumn/Winter	O
2011	O
Hologram	B-Algorithm
Runway	O
Show	O
"	O
,	O
which	O
included	O
life	O
size	O
2-D	O
projections	O
of	O
models	O
.	O
</s>
<s>
The	O
claim	O
that	O
holography	B-Algorithm
was	O
used	O
was	O
reported	O
as	O
fact	O
in	O
the	O
trade	O
media	O
.	O
</s>
<s>
In	O
Madrid	O
,	O
on	O
10	O
April	O
2015	O
,	O
a	O
public	O
visual	O
presentation	O
called	O
"	O
Hologramas	O
por	O
la	O
Libertad	O
"	O
(	O
Holograms	B-Algorithm
for	O
Liberty	O
)	O
,	O
featuring	O
a	O
ghostly	O
virtual	O
crowd	O
of	O
demonstrators	O
,	O
was	O
used	O
to	O
protest	O
a	O
new	O
Spanish	O
law	O
that	O
prohibits	O
citizens	O
from	O
demonstrating	O
in	O
public	O
places	O
.	O
</s>
<s>
Although	O
widely	O
called	O
a	O
"	O
hologram	B-Algorithm
protest	O
"	O
in	O
news	O
reports	O
,	O
no	O
actual	O
holography	B-Algorithm
was	O
involved	O
–	O
it	O
was	O
yet	O
another	O
technologically	O
updated	O
variant	O
of	O
the	O
Pepper	O
's	O
Ghost	O
illusion	O
.	O
</s>
<s>
Holography	B-Algorithm
is	O
distinct	O
from	O
specular	B-Algorithm
holography	I-Algorithm
which	O
is	O
a	O
technique	O
for	O
making	O
three-dimensional	O
images	O
by	O
controlling	O
the	O
motion	O
of	O
specularities	O
on	O
a	O
two-dimensional	O
surface	O
.	O
</s>
<s>
Holography	B-Algorithm
has	O
been	O
widely	O
referred	O
to	O
in	O
movies	O
,	O
novels	O
,	O
and	O
TV	O
,	O
usually	O
in	O
science	O
fiction	O
,	O
starting	O
in	O
the	O
late	O
1970s	O
.	O
</s>
<s>
Science	O
fiction	O
writers	O
absorbed	O
the	O
urban	O
legends	O
surrounding	O
holography	B-Algorithm
that	O
had	O
been	O
spread	O
by	O
overly-enthusiastic	O
scientists	O
and	O
entrepreneurs	O
trying	O
to	O
market	O
the	O
idea	O
.	O
</s>
<s>
This	O
had	O
the	O
effect	O
of	O
giving	O
the	O
public	O
overly	O
high	O
expectations	O
of	O
the	O
capability	O
of	O
holography	B-Algorithm
,	O
due	O
to	O
the	O
unrealistic	O
depictions	O
of	O
it	O
in	O
most	O
fiction	O
,	O
where	O
they	O
are	O
fully	O
three-dimensional	B-Algorithm
computer	I-Algorithm
projections	I-Algorithm
that	O
are	O
sometimes	O
tactile	O
through	O
the	O
use	O
of	O
force	O
fields	O
.	O
</s>
<s>
Examples	O
of	O
this	O
type	O
of	O
depiction	O
include	O
the	O
hologram	B-Algorithm
of	O
Princess	O
Leia	O
in	O
Star	O
Wars	O
,	O
Arnold	O
Rimmer	O
from	O
Red	O
Dwarf	O
,	O
who	O
was	O
later	O
converted	O
to	O
"	O
hard	O
light	O
"	O
to	O
make	O
him	O
solid	O
,	O
and	O
the	O
Holodeck	B-Algorithm
and	O
Emergency	B-Application
Medical	I-Application
Hologram	I-Application
from	O
Star	B-Operating_System
Trek	I-Operating_System
.	O
</s>
<s>
Holography	B-Algorithm
served	O
as	O
an	O
inspiration	O
for	O
many	O
video	O
games	O
with	O
the	O
science	O
fiction	O
elements	O
.	O
</s>
<s>
In	O
many	O
titles	O
,	O
fictional	O
holographic	B-Algorithm
technology	O
has	O
been	O
used	O
to	O
reflect	O
real	O
life	O
misrepresentations	O
of	O
potential	O
military	O
use	O
of	O
holograms	B-Algorithm
,	O
such	O
as	O
the	O
"	O
mirage	O
tanks	O
"	O
in	O
Command	B-Application
&	I-Application
Conquer	I-Application
:	I-Application
Red	I-Application
Alert	I-Application
2	I-Application
that	O
can	O
disguise	O
themselves	O
as	O
trees	O
.	O
</s>
<s>
Player	O
characters	O
are	O
able	O
to	O
use	O
holographic	B-Algorithm
decoys	O
in	O
games	O
such	O
as	O
Halo	B-Application
:	I-Application
Reach	I-Application
and	O
Crysis	B-Application
2	I-Application
to	O
confuse	O
and	O
distract	O
the	O
enemy	O
.	O
</s>
<s>
Starcraft	B-Application
ghost	O
agent	O
Nova	O
has	O
access	O
to	O
"	O
holo	O
decoy	O
"	O
as	O
one	O
of	O
her	O
three	O
primary	O
abilities	O
in	O
Heroes	B-Application
of	I-Application
the	I-Application
Storm	I-Application
.	O
</s>
<s>
Fictional	O
depictions	O
of	O
holograms	B-Algorithm
have	O
,	O
however	O
,	O
inspired	O
technological	O
advances	O
in	O
other	O
fields	O
,	O
such	O
as	O
augmented	B-General_Concept
reality	I-General_Concept
,	O
that	O
promise	O
to	O
fulfill	O
the	O
fictional	O
depictions	O
of	O
holograms	B-Algorithm
by	O
other	O
means	O
.	O
</s>
