Ray Rotator
The Ray Rotator is an imaginary device that rotates all incident rays. The object is a plane surface with either an elliptical or a rectangular shape. At the point a ray intersects the rotator, a "ray" coordinate system is created. The X, Y, and Z directions of this ray coordinate system initially are parallel to the local X, Y, and Z directions of the rotator, but the ray coordinate system is centered on the ray intercept point rather than the surface vertex.
The incident ray direction cosines are then rotated around the Z axis of the ray coordinate system. The rotation direction uses the right hand rule. This Z rotation also rotates the ray coordinate Y axis by the same angle. The rays are then rotated around the new ray coordinate Y axis resulting from the first Z direction rotation. If the rays are polarized, the polarization vector is also rotated. Note the ray's position is never modified; only the ray direction cosines.
The rotator object will not refract, absorb, attenuate, alter optical path or phase, or otherwise modify any property of the ray other than its direction and the direction of any associated electric field data. If the material is set to MIRROR, this object will reflect rays, and the rotation is applied after the reflection. Because the phase and optical path length are not modified, wavefront phase is not preserved by this object and thus only incoherent computations may be meaningful on the beam subsequent to the ray rotation.
The defining parameters are:
| Parameter # | Description | Face Name | Face # |
| 1-2 | The X/Y Half Widths. Make positive for a rectangular shape, negative for an elliptical shape. | NA | NA |
| 3-4 | The Z/Y direction rotation angles in degrees. | NA | NA |
Next: