Browse Prior Art Database

Uniform Line Illumination with Small Area High Radiant Sources

IP.com Disclosure Number: IPCOM000109400D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Prakash, R: AUTHOR [+2]

Abstract

Disclosed is an optical system for producing a uniform line image having high irradiance from a plurality of small area high radiant sources whose images overlap.

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Uniform Line Illumination with Small Area High Radiant Sources

       Disclosed is an optical system for producing a uniform
line image having high irradiance from a plurality of small area high
radiant sources whose images overlap.

      The output of laser diodes 10 are each collimated by lenses 15.
The wide divergent angle output of each laser diode is oriented along
the direction of image line 40.  Two such collimated laser diode
assemblies are positioned next to one another in one row.  Three more
laser diode collimated assemblies are positioned in a second row.
The rows are positioned to interleave the beams from each row further
down the optical path.  The two optical wave fronts are combined by
beam combiner 20, thereby causing the beams to overlap.  Concave
cylindrical lens 25 and convex cylindrical lens 30 expand the
combined wave front to achieve the desired image length.  Convex
cylindrical lens 35 focuses the wave front down, thus narrowing the
image width and increasing the image irradiance.  The laser diode
output intensity pattern 45 is Gaussian in shape.  Given matching
beam powers and widths, the beam to beam image spacing should be
about 1.1 times the individual beam image 1/e2 intensity radius for
uniformity to within a few percent 50.  Point and Lambertain
radiators with apertures can produce similar results.

      Several optical arrangement variations achieving the same
result are possible.  First, the beam expansion optics are...