Browse Prior Art Database

Mirror System for Compensating Pointing Instability of an Optical Beam

IP.com Disclosure Number: IPCOM000107916D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Guidotti, D: AUTHOR [+2]

Abstract

Disclosed is a simple, non-imaging mirror system which keeps a beam of light focused at one point in space as the direction of the beam changes over a wide range of angles (r, d). It is sometimes necessary to scan a beam from a point source P over a large area and keep the point of focus P' fixed on an aperture or detector. At other times unwanted directional instabilities may cause undesirable effects. These can be nulled at the point of focus P' of the mirror system described here.

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Mirror System for Compensating Pointing Instability of an Optical Beam

      Disclosed is a simple, non-imaging mirror system which keeps a
beam of light focused at one point in space as the direction of the
beam changes over a wide range of angles (r, d).  It is sometimes
necessary to scan a beam from a point source P over a large area and
keep the point of focus P' fixed on an aperture or detector.  At
other times unwanted directional instabilities may cause undesirable
effects.  These can be nulled at the point of focus P' of the mirror
system described here.

      FIG. 1.  Two sperical mirrors having identical or differing
radii of curvature can be used to focus a directional source of
illumination P onto a point of focus P'.  If the direction of the
source is altered by angle r (and/or d not shown), the point P' at
which the source is focused remains fixed.  This is shown by simple
construction.

      Some distinct advantages of the motion nulling mirror system
described here are as follows:
      Flexible beam steering ability.  The mirror pair can be used to
steer and stabilize a beam over nearly 4f steradians.  This
flexibility is not available with lenses.  When the source of
illumination is monochromatic and has a long coherence length
interference effects due to multiple reflections within lenses may
cause measurement difficulties in some applications.  These are
entirely eliminated by the spherical mirror pair in FIG. 1.
Elliptical o...