Calendar
SPIE Defense, Security, & Sensing
April 14-16, 2009
Booth 1037
Orlando, Florida
Visit SPIE Web site
Introduction to CODE V
April 27-May 1, 2009
Pasadena, California
See details or enroll
Advanced Topics in CODE V
May 4-8, 2009
Pasadena, California
See details or enroll
For a complete list of CODE V events worldwide, visit our Web site:
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Quick Tips on Non-Sequential Surface (NSS) Setup
Setting up NSS systems can sometimes be complicated. Here are some setup and troubleshooting tips for making sure your NSS ray trace is done correctly:
- Every NSS range requires an "exit port". Rays must hit this surface in order to exit the NSS range. It can be a refractive surface, a mirror, or a dummy surface located somewhere in space. Note, however, there is NO requirement for an "entrance port". Rays can enter the NSS range at any surface in the range, as with rays entering a segmented window.
- NSS does not support "virtual" ray tracing. All ray tracing must be "positive" in the sense that it must accumulate zero or positive optical path length (OPL) for each ray segment in the NSS range. This includes the initial entry into the NSS range. Be sure the sequential surface just prior to the NSS range is set to allow all rays from it to have a positive OPL into the NSS range.
- If an NSS system does not trace, try diagnosing it by tracing a real ray (Analysis > Diagnostics > Real Ray Trace) using object space directions (SIN) rather than a relative pupil ray (RSI). This is because the RSI ray trace requires the chief ray be traced, while SIN rays do not. The resulting SIN ray trace error message may help in finding setup issues:
- If the ray error is "NS ray from surface X missed all allowable surfaces", then there are several possible errors. The most likely problems are errors in the glass definitions (GL1, GL2) on some surfaces, an error in the exit port condition, or missing decenter data.
- If the ray error is "ray crossed undefined boundary" then there is probably an error in the glass designation (GL1, GL2) on some surfaces. Other possibilities are the need for virtual ray tracing on the entrance to the NSS range (not allowed) or steep rays which are outside the edge aperture for a surface they should hit.
- It is best practice to specify both normal clear apertures and edge (EDG) apertures on all NS surfaces. Edge apertures on NS surfaces define their physical size. Within an NSS range, rays that fall outside of an edge aperture physically miss the surface.
A good resource on modeling and diagnosing issues in NSS systems is the CODE V Advanced Topics Training presentation on this topic, which is available for download on www.oraservice.com.
Updates to the Customer Support Web Site
The following updates have been made to the ORA Customer Support Web site, www.oraservice.com, under CODE V Support:
- The Ghost_view macro, used to perform real ray trace ghost image analysis, has been updated to correct a crashing bug when run with some models in CODE V 10.0. The corrected version is available for download under Macro and User-defined Feature Downloads > Updated Sample Macros.
- The macro plasticprv.seq, used to define plastic material data via CODE V's Private Catalog, has been updated to include APEL plastics from Mitsubishi Chemical and ARTON plastics from JSR Corporation. It is available for download under Material Downloads.
- The white paper, CODE V Tolerancing: A Key to Product Cost Reduction, has been updated to include recent tolerancing enhancements in CODE V (polarization dependent loss, using Zernikes as performance metrics, etc.) as well as updated ray tracing speed data reflectin today's PCs. This paper can be downloaded under Technical Papers.
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