Chiral smectic A liquid crystal materials of the de Vries type (with molecules tilted relative to the layer normal) exhibit analog field-induced (electroclinic) optic axis rotation accompanied by an increase in birefringence. We identify two such de Vries smectic A* materials and use them to develop and test models for these characteristic electro-optic effects. These materials also exhibit colossal analog field-induced optic axis rotation in the lower temperature smectic C* phase, a consequence of polarization charge stabilization, and of polarization screening of the applied field in the liquid crystal.

Topics
Electro-optics, Liquid crystal phases, Thermotropic liquid crystals, Electrooptical effects, Birefringence
1.
A. J.
de Vries
,
Mol. Cryst. Liq. Cryst.
41
,
27
(
1977
).
Google Scholar
 
2.
R. B.
Meyer
,
L.
Liebert
,
l.
Strzelecki
, and
P.
Keller
,
J. Phys. (France)
36
,
L
-
69
(
1975
).
Google Scholar
 
3.
S. T. Lagerwall, Ferroelectric and Antiferroelectric Liquid Crystals (Wiley, New York, 1999).
4.
A. Fukuda, Proceedings of the 15th International Display Research Conference of the SID (Asia Display, 1995), p. 61;
S.
Inui
,
N.
Iimura
,
T.
Suzuki
,
H.
Iwane
,
K.
Miyachi
,
Y.
Takanishi
, and
A.
Fukuda
,
J. Mater. Chem.
6
,
671
(
1996
).
Google Scholar
 
5.
N. A.
Clark
et al.,
J. Mater. Chem.
9
,
1257
(
1999
).
Google Scholar
 
6.
MDW122C4: I↔ lim 77 °CSmA*↔ lim 71 °CSmC*↔ lim 68 °CSmIA*; MDW122C6: I↔ lim 86 °CSmA*↔ lim 74 °CSmC*↔ lim 68 °CSmIA*.
7.
P. Rudquist et al., Digest of Technical Papers of the SID International Symposium (1999) p. 409.
8.
Z.
Zhuang
,
J. E.
Maclennan
, and
N. A.
Clark
,
Proc. SPIE
1080
,
110
(
1989
).
Google Scholar
 
9.
N. A.
Clark
,
D.
Coleman
, and
J. E.
Maclennan
,
Liq. Cryst.
27
,
985
(
2000
).
Google Scholar
 
10.
N. A.
Clark
and
S. T.
Lagerwall
,
Appl. Phys. Lett.
36
,
899
(
1980
).
Google Scholar
 
11.
If the molecules are not rigid, i.e., if only the cores are tilting as in many SmC’s, then the change in d at the SmA–SmC transition is accommodated by less of the molecule, implying a correspondingly smaller SmA tilt of about 24°.
12.
S.
 
Garoff
 and
R.
 
Meyer
,
Phys. Rev. Lett.
 
38
,
848
(
1977
);
Google Scholar
 
S.
Garoff
and
R.
Meyer
,
Phys. Rev. A
19
,
338
(
1979
).
Google Scholar
 
13.
C.
 
Bahr
 and
G.
 
Heppke
,
Physica A
 
174
,
139
(
1991
);
Google Scholar
 
C.
 
Bahr
 and
G.
 
Heppke
,
Phys. Rev. A
 
44
,
3669
(
1991
);
Google Scholar
 
C.
Bahr
and
G.
Heppke
,
Phys. Rev. A
41
,
4335
(
1991
).
Google Scholar
 
14.
Such a field-induced increase in Δn due to biaxial ordering is observed in non-de Vries materials. See
F. J.
Bartoli
,
J. R.
Lindle
,
S. R.
Flom
,
J. V.
Selinger
,
B. R.
Ratna
, and
R.
Shashidhar
,
Phys. Rev. E
55
,
R1271
(
1997
).
Google Scholar
 
15.
J. V.
Selinger
,
P. J.
Collings
, and
R.
Shashidhar
,
Phys. Rev. E
64
,
061705
(
2001
). In this paper an observed increase of effective cone angle θA with applied field similar to that of our Fig. 2 is interpreted by keeping θA fixed at its high field value and making the local dielectric tensor sufficiently biaxial. Any such biaxiality in our experiments ought to show up in the SmC phase as well, increasing Δn/Δnmax at low field. This is not observed.
Google Scholar
 
This content is only available via PDF.
© 2002 American Institute of Physics.
2002
American Institute of Physics
You do not currently have access to this content.