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OPTICALLY ACTIVE DETECTORS OF INCREASED SENS

IP.com Disclosure Number: IPCOM000023130D
Original Publication Date: 1976-Oct-31
Included in the Prior Art Database: 2004-Mar-27
Document File: 2 page(s) / 224K

Publishing Venue

Xerox Disclosure Journal

Abstract

In many optically active detectors, the thickness of the active element needed tp provided the desired degree of change in optical property cannot be easily provided in a single thickness. For example, a film of cholesteric liquid crystalline

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SCLOSURE JOURNAL

OPTICALLY ACTIVE DETECTORS Proposed Classification

Q~INCREASED SENSITIVITY U.S. Cl, 350/16OLC
James E. Adams mt. Cl, G02h 5/23
Werner E. L. Haas

In many optically active detectors, the thickness of the
active element needed tp provided the desired degree of
change in optical property cannot be easily provided
in a single thickness.

For example, a film of cholesteric liquid crystalline
material in the Grandjean texture will rotate the plane
of polarization of monochromatic light through an angle
which depends on the relationship of the inversion
wavelength of the film ( A~) and the wavelength ( ~

of the incident light.

This relationship is given by:

e (,\~=

where is rotation per unit thickness, ~

  p being the pitch of the cholesteric helix, ~ is the
index of refraction, and Q( is related to the birefrin~
gence. For maximum sensitivity it is desirable that the
sample be as thick as possible. Unfortunately, it is not
possible to maintain the Grandjean textures in samples
of more than a few mils in thickness.

The effective thickness of the Grandjean sample, and
other active elements, can be increased by the use of
fibre optics in which the light input is passed through
the sample from the same side of the sample in consecu~
tive, multiple passes.

Volume 1 Numbers 9/10 September/October 1976 59

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60 XEROX DISCLOSURE JOURNAL

Volume 1 Numbers 9/10 September/October 1976

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