Browse Prior Art Database

Refraction-Based Optical Switch

IP.com Disclosure Number: IPCOM000120066D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 83K

Publishing Venue

IBM

Related People

Rossi, RV: AUTHOR

Abstract

Described is a device which performs the switching of a light signal by either reflecting or transmitting such signal. The switching is accomplished by the shape of the switching device and by the optical characteristics of the material used to fabricate it.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Refraction-Based Optical Switch

      Described is a device which performs the switching of a
light signal by either reflecting or transmitting such signal.  The
switching is accomplished by the shape of the switching device and by
the optical characteristics of the material used to fabricate it.

      The body of the switching device is composed of electro-optic
or photorefractive material.  The switching device is a prism capable
of total internal reflection at the ordinary index of refraction of
the material.  By subjecting the switching device to an appropriate
electrical field or light radiation excitation we induce a change to
the extraordinary index of refraction.  We expect a return to the
ordinary index of refraction once the excitation is removed.

      The figure illustrates the principle of operation of the
device.  A simple reflector prism 'A' fabricated between the
single-mode planar optical waveguides 'B' and 'C' (cladding not
shown).  The index ellipsoid in the material forming prism 'A' is
oriented so that the axis which displays the bimodal index of
refraction is contained in the plane of the figure when no excitation
is provided and is parallel to the direction of propagation of the
optical signal to be switched.  Plates 'D' and 'E' are necessary if
we want to use the electro-optic effect in modifying the index of
refraction of the material forming prism 'A'.  Plates 'D' and 'E'
will then be used to provide the appropriate electric field to impart
the change in the index of refraction of the electro-optic material
in the prism.  The position of plates 'D' and 'E' may vary depending
on the choice of electro-optic material used to fabricate prism 'A'.
Not depicted is the use of another optical waveguide in case the
opto-refractive characteristics of the material used to fabricate
prism 'A' are to be used.  The position of this optical waveguide can
vary with the selection of...