Browse Prior Art Database

Combined Beam Circularizer and Polarization Isolator for use with Diode Lasers

IP.com Disclosure Number: IPCOM000107763D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 81K

Publishing Venue

IBM

Related People

Latta, M: AUTHOR

Abstract

Most diode laser systems require circularization (anamorphic expansion or compression) of the beam in order to perform the intended optical function. In addition, many diode laser systems require optical isolation from unwanted return light reflected from succeeding elements in an optical train. These two functions are usually performed by separate sets of optical elements. It is the intent of the current disclosure to combine these two functions into a common set of optical elements.

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Combined Beam Circularizer and Polarization Isolator for use with Diode Lasers

       Most diode laser systems require circularization
(anamorphic expansion or compression) of the beam in order to perform
the intended optical function.  In addition, many diode laser systems
require optical isolation from unwanted return light reflected from
succeeding elements in an optical train.  These two functions are
usually performed by separate sets of optical elements.  It is the
intent of the current disclosure to combine these two functions into
a common set of optical elements.

      The circularizing function can be performed by the use of 2
prisms which expand (or compress) the beam anamorphically.  If these
prisms are made of Faraday glass and placed between input and output
polarizers, then they will serve as a Faraday polarization isolator
as well.  Most Faraday isolators use multiple passes through the
glass to minimize the package size.  This can be done, as well, by
making the prism as a wedge.  Also, since the circularizing function
is provided by using an inclined surface this same input surface can
be used as an input polarizer if the surface is properly coated.

      Two configurations are shown below in Fig. 1 and Fig. 2.  Fig.
1 shows a beam expansion configuration, and Fig. 2 shows a beam
compression configuration.  In Fig. 1 the first prism produces the
square root of the total beam expansion, and produces the Faraday
rotation by virtue of...