Xarmdemo.len - An extended aperture parabola

Xarmdemo.len - An extended aperture parabola

An increasing number of optical systems require ray tracing beyond 90 degrees. The nikofish.len example shows how OSLO accommodates optical systems that have a field of view greater than 90 degrees. This example shows how OSLO accommodates optical systems that have an aperture greater than 90 degrees. Often, such systems are found in illumination applications where high-quality image formation is not required, such as the design of luminaires or light collectors.

The general operating condition xarm (extended aperture ray aiming mode) sets up a system of fractional aperture coordinates based on a maximum beam angle (xaba), measured relative to the positive z-axis at the object surface. When xarm is on, fractional coordinates are measured similarly to the tilt angles tla and tlb. A fractional coordinate of +1.0 corresponds to a ray angle equal to xaba above the z-axis, and a fractional coordinate of -1.0 corresponds to a ray angle equal to xaba below the z-axis.

Extended aperture ray aiming is limited to tracing single rays and computing spot diagrams. There is no reference ray, so analyses such as ray fans have no meaning. The figure below shows a parabolic mirror used in conjunction with extended aperture ray tracing. Since the mirror is to the left of the object, it must be an alternate intersection surface. Note that the mirror has a central obstruction to block rays.

*LENS DATA
Extended aperture ray aiming
SRF      RADIUS      THICKNESS   APERTURE RADIUS       GLASS SPE   NOTE
  0        --        -50.000000    1.0000e-06             AIR

  1    100.000000    2.0000e+03    380.000000 AKX  REFL_HATCH   *

  2        --            --        380.000000

*CONIC AND POLYNOMIAL ASPHERIC DATA
SRF        CC          AD          AE          AF          AG
  1      -1.000000      --          --          --          --

*SURFACE TAG DATA
  1     ASI   1

*APERTURES
SRF   TYPE APERTURE RADIUS
  0     SPC   1.0000e-06
  1     SPC   380.000000  CHK
     Special Aperture Group 0:
     A  ATP      Ellipse  AAC     Obstruct  AAN       --
        AX1   -24.000000  AX2    24.000000  AY1   -24.000000  AY2    24.000000
  2     SPC   380.000000

*OPERATING CONDITIONS: GENERAL
   Image surface:                    2    Aperture stop:                    1
.
   Telecentric entrance pupil:     Off    Wide-angle ray aiming mode:     Off
   Aper check all GRIN ray segs:   Off    Extended-aper ray aiming mode:   On
   Plot ray-intercepts as H-tan U: Off    XARM beam angle:         150.000000
   Source astigmatic dist:      --        Ray aiming mode:          Aplanatic
   Temperature:              20.000000    Pressure:                  1.000000

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