Browse Prior Art Database

Efficient Compact and Uniform Line Illumination with a Single Laser Diode

IP.com Disclosure Number: IPCOM000107841D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Sanford, JL: AUTHOR

Abstract

Disclosed is an optical system for producing an efficient, compact and uniform line image having high irradiance from a single laser diode.

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Efficient Compact and Uniform Line Illumination with a Single Laser Diode

       Disclosed is an optical system for producing an
efficient, compact and uniform line image having high irradiance from
a single laser diode.

      In Fig. 1 the output of laser diode 10 is captured by
cylindrical lens 20.  The wide divergence angle output of the laser
diode is oriented along the axis of cylindrical lens 20.  The narrow
divergence angle output is focused to form an intermediate line image
30.  A second cylindrical lens 40 refocuses the intermediate image to
create the final line image 50.  The final image length, L, is a
function  of laser diode angle of divergence, optical path length and
the irradiance uniformity desired.  The final image width is a
maximum of 40 mm over the image length.  Some additional
characteristics of the final image 50 are that it may be polarized
and monochromatic depending upon the laser diode and that it is
incrementally collimated along the line length direction.

      Shown in Fig. 2 are high reflectance folding mirrors 60 and 70
that produce a compact illumination package for long line images.  In
order to maximize optical power coupling efficiency for wider
divergence angle diodes, the laser diode 10, cylindrical lens 20 and
folding mirror 70 are displaced laterally and/or towards the other
components 40, 50, and 60 to reduce the optical path length.

      Additionally, passive or active transmissive and/or reflective
a...