LIQUID GATE CHOICE OF INDEX OF REFRACTION OF LIQUID TO SUPPRESS DIFFRACTION SPECTRUM

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A002700020041-6
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 9
• Document Creation Date: December 28, 2016
• Document Release Date: June 26, 2002
• Sequence Number: 41
• Publication Date: September 13, 1963
• Content Type: MEMO

Approved For Release 2002/07/12 : CIA-RDP78BO4747AO02700020041-6
Declass Review by NIMA / DoD
Tests were de on a si if saggle of each of 5 films. A R chi gratin was
printed an each sale d then blessched off so as to leave a. transparent thickneaas
grti in the ca ~sion., when piaacexd in the negative plait of fl coherent light
ular er (A.= 6328A) the grating caused a diffraction spectrum, the intensity
of which was determined by a snit able photocell. Ligoldrr of various indices of
ictfraction were applied to the film (both sIdea) to suppress the spectrum; the
results were as follows:
ME
0 4400
1 N X FOR G
1~?W;
ST
I
8U 4ESTED
USEFUL RANGE
1.66
1:, 62 to 1. 70
1 A.
ly32 to 1.42
1.54 to 1.62
1 a 641 (Approx)
N I A
12,~:~Kao 4401
4 4 04
X-L 5401
n X. 8401
1.56 to 1.62
STAT
STAT
is
;/13163
Approved For Release 2002/07/12 : CIA-RDP78BO4747AO02700020041-6
STAT
 Approved For Release 2002/07/12 : CIA-RDP78B0 477A002700(
COHERENT LIGHT ENLARGER Mfl) SPATIAL FILTER
3rd Progress Report: 13 Aug to 9 Sept 63
The breadboard enlarger has been lined up with lens
enlargeanentc have been made in coherent light0 These
ants show the general characteristics to be expected0
The various artifact s are being traced by further eexperimentation
which is currently in pro ressss0 A break down of the E=cas e:rr
m,ntd shutter has caused some delay.
The optical design for the prototype has been completed,
for lens #1,~, h t the design for lens #2 is not yet complete0
Pens #1 design calls for s~.x spherical elements and should
therefore be much easier to fabricate than an asptzeric lens design
which had been anticipated in the proposal 0 Lens #1, the two
collimating lenses, the two cell windows, and a plate for the
spatial filter plane were released for optical fabrication0
The optical design for lens #2 of the prototype is not
yet complete because the optical designer has been unable to work
on it0 If lens #2 is a simple lens (and this is expected) another
t*. weeks delay should not affect the schedule. However, the,
absence of a design is delayin,,3 the opts-isecbsuical layout, cell
fabrication, and those mechanical design aspects contingent on its
engineering analysis and customer review, which is
scheduled or t e e of 23- Sept; er s te~tt:ative~)r schedule d
for 25-26 September.
STAT
STAT
STAT
Approved For Release 2002/07/12 : CIA-RDP78$04747A002700020041-6
 Approved For Release 2002/07/12: CIA-RDP78B0474
COHERENT LIGHT ENLARGER AND SPATIAL FILTER
2nd Progress Report : 9 Jul to 12 Aug 63
The breadboard enlarger has been act up except for Lens #l.
Without lens #1, the spectrum is formed by Lens #2, and this spectrum
was used to find the correct liquid index for each of the five films
so far provided by the, customer, using bleached Ronchi gratings.
A 16-inch focal length collimator objective is now being
used as a temporary substitute for Lens #1. This will be used to
find approximate exposure and focus, and to make trial enlarge ,eats of
test images, which have also been printed on the supplied film.
Lens #1 for the breadboard is now in the final stages
of figuring and its lateness, if held to one more week, will not
affect schedule.
The optical design for Lana #1 and Lens #2 of the Prototype
is now due one week late, but the Optical Designer is working through
vacation. By some schedule manipulation, we can probably absorb one
further week of delay without prejudice to final delivery.
A trial spatial filter was made, but has not yet been fully
evaluated. As it appears to be irregular, improved coating jigs are
being fabricated.
.Use of the required film has not been provided, and this
has necessitated "borrowing" from other Special Projects film.
12-August 1
STAT
STAT
Approved For Release 2002/07/12 : CIA-RDP78B04747A002700020041-6
 Approved For Release 2002/07/12 : CIA-RDP78BO4747AO02700020041-6
pbgo
?f p,~ #r~s t v nd th 'ern
In a recent technical memo* it was stated that as a result of he Lorenz-
Lorenz law
rc2-1
n2+2
0.368 2'.,07 z 10-4
the coefficient of index of refraction
, n, variation with t rxnta re,
was
A--ft in 4 +D 2_ 2
6n
where $ is the voles thermal expansion coefficient Of the liquid.
(constant) z density,
-0.76 x 10
The purpose of this memo is to call attention to the fact that the Loreaa-
,o az law is not accurately valid and that, there forejEquation ( is subject
to error. To illustrate this consider experimental date for water and
99+% pure Ethyl alcohol,, at 20?C
n4+xe2-2
predicted observed
9 4
Alcohol 10360
(1)
(2)
---1.0 x 10-4
0,405 1012 x 10-3 -4.5 x 10-4
-4 ~OF6 x 10-4
STAT
--106 __.,., STAT
(note typographical error in q. 1)
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 Approved For Lease 2002/07/12 : CIA-RDP78B04747p2700020041-6
arch
Page 2 of 2
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s
.C ac}t' 1-8 thto #=e ' a # a . and F?nM 3x!:iEr hf Sam +
. d.C " y 3 Cti:3 b impr v d
t
~4~a`~ ci#tkr$~ ?pproac7ced fi x UT uid' 9 L"-)i1{Ca T hit ew g point. Tbit could explain
Y ""~ / pr-`Od1cf:?
eras 3o b
.
a# rfo : alcohol t l ~: :~tff although
s; ,t eti .. s ~a . a x w tz,4,u .Yr a;n..ore r_o p1o-w thsr, has bs:ora indicates
STAT
Approved For Release 2002/07/12 : CIA-RDP78BO4747AO02700020041-6
 Approved For Release 2002/07/12 : CIA-RDP78BO4747AO02700020041-6
CHANGE OF LIQUID'S REFRACTIVE INDEX WITH TEMPERATURE
In many coherent optical systems, it is desirable to have
.squid gates in which objects of non-uniform thickness are immersed
In a liquid having the same refracf,ive index. Thus, for instance, only
transparency differences recorded on film will affect the transmitted
light and the thickness irregularities will not alter the optical phase.
ecause the refractive index is temperature sensitive, it may be necessary
to control the temperature avid/or temperature uniformity of the liquid;
and for. this reason, the change of refractive: index with temperature for
a liquid was investigated.
the Lorenz-Lorentz law states
n2_1.
c
n2+G.
:here n is taae refractive inch:, e the density, and c a constant. If
7 is the t perature, and the coefficient of cubical (volume) 4txpension,
do dais
I!?
Thus, do/d9~, a quantity which is seldoam: tabulated, can be evaluated in
warms oar n .read both of which are cosy only tabulated. The bracketed
ter-at has been evaluated:
a~, 1.0 1.1 1,2 1.3 1.4 1.3 1.6 107
5racketeer term 0 0.10 0.21 0.33 0.45 0.59 0.74 0. 91
STAT
STAT.
Approved For Release 2002/07/12 : CIA-RDP78BO4747AO02700020041-6
n'' + n2 - 2
 Approved Folease 2002/07/12 : CIA-RDP78B047#002700020041-6
0, ad,
";c t, , is not I,iket"
v
4
&?'td 4 x.,; i'$ ? ?r;A ?B ~ ,~u.tar~
A57' 1,S' t ? tot ;i Y'd .8 ,".riC
p
le, Liq ;fd wiu-.h. j.Oxj r should b
4 ,v ., the c ;e ii& opIR egi path 1.1 be
Cum Q.,z JL+ ? L -