Influence of elastic deformation on the residual ellipticity of polished optical materials
The elastic deformation of thin mirrors is widely used in systems of adaptive optics, however, there are no data upon investigations of influence of elastic deformations on parameters of reflected polarised light in the literature. Using the method of ellipsometry, the influence of elastic deformati...
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| Опубліковано в: : | Semiconductor Physics Quantum Electronics & Optoelectronics |
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| Дата: | 2003 |
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| Мова: | English |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2003
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| Цитувати: | Influence of elastic deformation on the residual ellipticity of polished optical materials / V.P. Maslov, A.Z. Sarsembaeva, F.F. Sizov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2003. — Т. 6, № 4. — С. 514-516. — Бібліогр.: 7 назв. — англ. |
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Maslov, V.P. Sarsembaeva, A.Z. Sizov, F.F. 2017-05-28T16:35:57Z 2017-05-28T16:35:57Z 2003 Influence of elastic deformation on the residual ellipticity of polished optical materials / V.P. Maslov, A.Z. Sarsembaeva, F.F. Sizov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2003. — Т. 6, № 4. — С. 514-516. — Бібліогр.: 7 назв. — англ. 1560-8034 PACS: 42.86.+b, 78.20.-e https://nasplib.isofts.kiev.ua/handle/123456789/118078 The elastic deformation of thin mirrors is widely used in systems of adaptive optics, however, there are no data upon investigations of influence of elastic deformations on parameters of reflected polarised light in the literature. Using the method of ellipsometry, the influence of elastic deformation on the residual ellipticity of polished samples made of optical materials was studied. The results obtained during the researches have shown that the application of elastic deformations leads to essential changes of the minimum ellipticity tgp of polished samples, which testifies to the necessity to take into account this circumstance for devices of adaptive optics, input windows, cryostats and other optical parts working with the changing temperature. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Influence of elastic deformation on the residual ellipticity of polished optical materials Article published earlier |
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Influence of elastic deformation on the residual ellipticity of polished optical materials |
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Influence of elastic deformation on the residual ellipticity of polished optical materials Maslov, V.P. Sarsembaeva, A.Z. Sizov, F.F. |
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Influence of elastic deformation on the residual ellipticity of polished optical materials |
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Influence of elastic deformation on the residual ellipticity of polished optical materials |
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Influence of elastic deformation on the residual ellipticity of polished optical materials |
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Influence of elastic deformation on the residual ellipticity of polished optical materials |
| title_sort |
influence of elastic deformation on the residual ellipticity of polished optical materials |
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Maslov, V.P. Sarsembaeva, A.Z. Sizov, F.F. |
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Maslov, V.P. Sarsembaeva, A.Z. Sizov, F.F. |
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2003 |
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English |
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Semiconductor Physics Quantum Electronics & Optoelectronics |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
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Article |
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The elastic deformation of thin mirrors is widely used in systems of adaptive optics, however, there are no data upon investigations of influence of elastic deformations on parameters of reflected polarised light in the literature. Using the method of ellipsometry, the influence of elastic deformation on the residual ellipticity of polished samples made of optical materials was studied. The results obtained during the researches have shown that the application of elastic deformations leads to essential changes of the minimum ellipticity tgp of polished samples, which testifies to the necessity to take into account this circumstance for devices of adaptive optics, input windows, cryostats and other optical parts working with the changing temperature.
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1560-8034 |
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https://nasplib.isofts.kiev.ua/handle/123456789/118078 |
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Influence of elastic deformation on the residual ellipticity of polished optical materials / V.P. Maslov, A.Z. Sarsembaeva, F.F. Sizov // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2003. — Т. 6, № 4. — С. 514-516. — Бібліогр.: 7 назв. — англ. |
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AT maslovvp influenceofelasticdeformationontheresidualellipticityofpolishedopticalmaterials AT sarsembaevaaz influenceofelasticdeformationontheresidualellipticityofpolishedopticalmaterials AT sizovff influenceofelasticdeformationontheresidualellipticityofpolishedopticalmaterials |
| first_indexed |
2025-11-25T20:43:29Z |
| last_indexed |
2025-11-25T20:43:29Z |
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1850530821474091008 |
| fulltext |
Semiconductor Physics, Quantum Electronics & Optoelectronics. 2003. V. 6, N 4. P. 514-516.
© 2003, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine514
PACS: 42.86.+b, 78.20.-e
Influence of elastic deformation on the residual ellipticity
of polished optical materials
V.P. Maslov, A.Z. Sarsembaeva, F.F. Sizov
V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41, prospect Nauki, Kiev, Ukraine,
Phone/fax: +38 044 2650555, E-mail: sizov@isp.kiev.ua; maslov@isp.kiev.ua
Abstract. The elastic deformation of thin mirrors is widely used in systems of adaptive optics,
however, there are no data upon investigations of influence of elastic deformations on param-
eters of reflected polarised light in the literature. Using the method of ellipsometry, the influ-
ence of elastic deformation on the residual ellipticity of polished samples made of optical
materials was studied. The results obtained during the researches have shown that the appli-
cation of elastic deformations leads to essential changes of the minimum ellipticity tgρ of
polished samples, which testifies to the necessity to take into account this circumstance for
devices of adaptive optics, input windows, cryostats and other optical parts working with the
changing temperature.
Keywords: minimum ellipticity tgρ, elastic stresses, optical materials.
Paper received 01.10.03; revised manuscript received 27.11.03; accepted for publication 11.12.03.
1. Introduction
The elastic deformation of thin mirrors is widely used in
systems of adaptive optics, however, in the literature there
are no data about investigations of influence of elastic
deformations on parameters of reflected polarised light
of the object, ellipsometry (reflective polarimetry) is an
optical method of measurement. It is based on the analy-
sis of beam polarisation changes of polarised light after
its reflection from the studied surface.The ellipsometric
method was chosen to control the quality of processing
optical surfaces. As a criterion of quality, we selected the
minimum ellipticity tgρ [1�3].
The main aim of the investigation was to study the
influence of elastic deformations on the residual ellipti-
city of polished samples made of optical materials to make
conclusions about the possibilities to use this method to
control elastic deformations in optical products.
2. Method of ellipsometric investigations
When an electromagnetic wave is leflection from an arbi-
trary reflecting system (Fig. 1) [2,3], a phase difference
appears between components of the electric vector, per-
pendicular and parallel to the planes of incidence, which
generally leads to the elliptical polarisation of this wave.
Reflective indexes Rp and Rs of a system and phase differ-
ence ∆ are by the basic equation of ellipsometry:
∆== i
s
p
etg
R
R
ψρ . (1)
Angles ψ è ∆ are called ellipsometric parameters of
the system.
The account of multiple reflections inside a layer on
the first and second boundary surface allows to express
reflective coefficients of all the system, that enter in to the
basic ellipsometric equation (1) through the Fresnel re-
flection coefficients inherent each interface r1, r2 and depth
of the layer. In this case, equation (1) gets a view:
δ
δ
δ
δ
ψ
i
ss
i
ss
i
p
i
ppi
err
err
er
err
etg
−
−
−
−
∆
+
+
⋅
+
+
=
21
21
1
21 1
1
(2)
where ( ) 2/122
2
2
1 sin
4
ϕ
λ
πδ nn
d
−= � phase difference in
the layer.
V.P. Maslov et al.: Influence of elastic deformation on the residual ellipticity...
515SQO, 6(4), 2003
As a result of transformations from (2) the angle de-
pendencies for the phase difference ∆ and angle ψ could
be obtained:
,
))(1(
sin))(1(4
1
))(1(
sin))(1(4
2
2
22
2
2
1
2
2
2
1
2
2
2
1
_
2
2
22
2
2
1
2
2
2
1
2
2
2
1
_
−−
−−
+=
−−
−−
=
∆−∆
ntgnn
tgnnnnd
tgtg
ntgnn
tgnnnnd
tg
ϕλ
ϕϕπ
ψψ
ϕλ
ϕϕπ
(3)
where
_
ψ and
_
∆ � ellipsometric angles for substrate.
At the Brewster angle (tgϕBr = n2/n1) from the second
equation of the system (3) the formula for minimum value
of ellipticity follows:
2/12
22
2
2
1
2
1
2
2
2
1 )1(
)1(
))(1(
+
−
−−
= n
nn
nnnd
tg
λ
π
ψ (4)
Relation of Fresnel reflection coefficients of p- and s-
components of the electric vector, tgρ and the phase dif-
ference between them can be counted by usage of the metal-
optics method. The photoelectric method of Beattie and
Conn is the most suitable among them. The modification
of this method, that allows to apply it to transparent di-
electrics was used in this work [4,5].
The directly measured values are intensities of radia-
tion reflected from the sample I0, I45, I90, measured at
three azimuths of the analyser αa (equal, accordingly, to
0°, 45°, 90°) concerning the plane of incidence and fixed
azimuth the polariser β = 45°. Ellipsometric parameters
are calculated by the formulas:
900
90045
90
0
2
2
cos
II
III
I
I
tgtg
−−
=∆
= ψρ
(5)
As the measurements of ellipsometric parameters are
carried out within the limits of the Brewster angle, where
cos∆ passes through zero point, the error of phase differ-
ence is minimum, and the following condition is realised:
ψρ tgtg = (6)
3. Experimental results and discussion
The comparative estimation of deformation influence of
substrates made of different materials on the ellipsometric
parameters (EP) was performed. The researches were
made for optical glass Ê8 (analogue ÂÊ7), silica glass
ÊÂ and sitall ÑÎ115Ì (analogous to ZERODUR). Se-
lection of materials for these samples was based on such
facts: glass and glassceramic are model samples and they
have practical use in instrument making, particularly for
manufacturing adaptive mirrors. 25 mm diameter sam-
ples were previously polished by electroemery with stip-
pling Ì28 and Ì10, and then glazed with polirit on the
depth of 30 m. Thickness of samples was 2 mm. Flank
surfaces of samples were made with angle 3° to the pol-
ished surface and was blackened with a varnish. Samples
were designed with the requirement on rejection from
planes:
N = 1...5;
∆N = 0,5�1
where N � interferential Newton rings; ∆N � rejection
of interferential rings [6].
The laser null-ellipsometer LEF-3M-1 (λ = 6328Å)
was used for the measurements.
It is known, that the value of ellipticity decreases with
the increase of polishing depth down to 8�10 µm, and
with further increase of the depth becomes stabilised, re-
maining a constant for deep-polished samples [2]. Such
nature of ellipticity changes is explained by decreasing
of defects concentration with increase of polishing depth.
Thus, there was a vague role of residual stresses, which
appears as the result of mechanical operation.
Studying of EP changes in surface layers of samples
was conducted using the special device (Fig. 2).
Samples were pasted by the blackened surface to the
frame 1 of the device. Using the abutment screw tensile 2,
the elastic deformation was created on the surface of a
polished sample. Sample flatness changed.
The control of sample deformation was conducted
using a tentative glass for observation of interferential
Newton rings in the air interspace between the studied
sample and tentative glass. 5 µm deformation responded
E
j j
E
R
R
d
p
s
1
2
p
s
Fig. 1. Reflection of a plane harmonic wave from a homogeneous
layer (n1, n2 � refractive indexes, and d � depth of the sample).
1
2
3
4
5
Fig. 2. Device for the deformation of surfaces of polished sam-
ples: 1 � the frame of the device, 2 � the screw, 3 � the sample, 4
� glue, 5 � the paper gasket.
516
SQO, 6(4), 2003
V.P. Maslov et al.: Influence of elastic deformation on the residual ellipticity...
a crimp of the studied sample up to 20 interferential rings.
The increase of the load till the appearance of the greater
number of Newton rings can cause to the appearance of
microcracks and exceeded material stability in condi-
tions of the central crimp caused by the pressure (80�
100) MPa. Thus, the applied stresses and deformations
up to 5 ìm were with the elastic, range.
In course of experiments, the statistical method of
analysing the results was used: the random component of
the error limit at the confidence coefficient 0.95 was equal
to 10 % from the value of EP.
The results are shown in the Table 1.
During deformation of the polished surface of sitall,
the main angle Ô a little bit increases and returns to the
initial value after removing the deformation. The ellip-
ticity at deformation is considerably increased and re-
turns to initial value after removing the deformation.
For polished surface of silica glass, the main angle
before deformation was less then the Brewster one. Its
increase with loading can testify the approach of matter
properties to the bulk ones. It is related with relaxation
of defects caused by the mechanical treatment at a pad-
ding influence of bending external stresses.
For polished surface of the glass Ê8, the main angle
is less than the Brewster angle. When applying the dis-
torting efforts and their following removal the main an-
gle changes a little. The ellipticity changes similarly to
those of sitall and silica glass.
The obtained data have shown, that there is a relative
shift of tgñ for studied samples. The largest shift is for
sitall, and the smallest one is for the glass Ê8. In our
opinion, it is related with a bulk structure of the matter:
the minimum ellipticity shift will correspond to the most
homogenous matter.
It is necessary to mark such experimental fact, that
after removing of external stress the dispersion of
ellipsometric parameters of studied samples for the above
mentioned materials become smaller than before defor-
mation.
4. Conclusions
The application of incurvating elastic deformations, of
which value approximates to destructive values, leads to
the essential changes of the minimum ellipticity tgρ for
the polished samples made of sitall ÑÎ115Ì, silica glass
ÊÂ and glass Ê8. This is related with a bulk structure of
the matter. The main angle Ô practically does not chan-
ge. The returning of tgñ practically to initial values after
removing the load is observed. The relative error of ex-
perimental results of minimum ellipticity tgñ researchers
decreases, which can testify to an increasing homogene-
ity of upper layers of the studied materials after applying
of mechanical loads in the area of elastic deformations.
So it�s possible to use this method to control the elastic
deformations in optical products.
References
1. T.V. Vladimirova, N.Ya. Gorban, V.P. Maslov, T.S. Melnik,
V.A. Odarich, The research of the optical proper ties and
building of sitall // OMP, 1979, ¹9, p.31-33;
2. Fundamentals of an ellipsometry. Under edition of
A.V. Rzhanov // Novosibirsk, Nauka, 1979;
3. T.V. Andreeva, V.A. Tolmachev, Methodological aspects
of ellipsometric experiment on optical materials // OMP, 1986,
¹10, p. 36-39;
4. V.A. Odarich, Measurement of small ellipsometric param-
eters by a photoelectric method // Zav.lab., 1977, ¹43, p.1093;
5. Beattie G.R, Conn G.K.T., Phil. Mag., 1955, 46, p. 222-225;
6. The reference book of the technologist � optician, under
edition of S.M. Kuznezcova, M.A. Okatova, Leningrad,
Magnitostroenie, Leningrad department, 1983, 414 pages;
7. A.I. Belyaeva, A.A. Galuza, T.G. Grebennik, V. Pyuriyev,
Optical constants of surface layer on gadolinium gallium
garnet: ellipsometric study // Semiconductor Physics, Quan-
tum Electronics and Optoelectronics, 1999, 2(4), p. 61-65.
Table 1. Dependence of ellipsometric parameters of sitall ÑÎ115Ì, silica glass ÊÂ, glass Ê8 on their deformation. tgρρρρρ - minimum
ellipticity, Ô°°°°° � main angle.
Deformation Sitall ÑÎ115Ì Silica glass ÊÂ Glass Ê8
µm Number of tgρ⋅10�3 Ô, (degrees) tgρ⋅10-3 Ô, (degrees) tgρ⋅10-3 Ô, (degrees)
interf. rings
0 0 3.5±0.4 57°12′±3 3.50±0.4 55°33′±3 4.3±0.4 56°41′±3
2.5 10 4.1±0.4 57°13′±3 4.16±0.4 55°39′±3 4.5±0.4 56°41′±3
5 20 5.0±0.5 57°18′±3 4.46±0.5 55°45′±3 4.8±0.5 56°42′±3
After deformation 3.6±0.1 57°11′±3 3.33±0.1 55°38′±3 4.26±0.1 56°42′±3
removing
Relative shift of 42.8% � 31.4% � 11,6% �
tgñ at deformation
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