Calendar
SPIE Europe Optical Systems Design
Sept. 2-5, 2008
Booth 109
Glasgow, Scotland
Sept. 2, 2008
Featuring a "Practical Topics in Imaging and Illumination Design" presentation
Visit SPIE Web site
Introduction to CODE V
Sept. 29-Oct. 3, 2008
Pasadena, California
See details or enroll
Advanced Topics in CODE V
October 6-10, 2008
Pasadena, California
See details or enroll
OSA Frontiers in Optics
Oct. 19-23, 2008
Booth 514
Rochester, New York
Visit Web site
Introduction to CODE V
Nov. 3-4, 2008
Salzburg, Austria
Contact OEC for registration
CODE V User Day
Nov. 5, 2008
Salzburg, Austria
Contact OEC for registration
Selected Advanced Topics in CODE V
Nov. 6-7, 2008
Salzburg, Austria
Contact OEC for registration
SPIE Photonics West 2009
Jan. 24-29, 2009
Booth 615
San Jose, California
Visit SPIE Web site
For a complete list of CODE V events worldwide, visit our Web site:
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Quick Tips for CODE V Optimization
For the vast majority of optical systems, CODE V's smart optimization defaults will provide a good solution quickly. However, there are a couple of lesser known optimization commands that can often increase the rate of convergence for some types of optical systems. This can add to some time savings for long optimization runs, or when using CODE V's Global Synthesis feature.
Decoupling Curvature Variables
For most optical systems, CODE V optimization achieves its best results when utilizing lens bending of elements (or air spaces) as a variable rather than individual surface curvatures. Lens bending produces variables that are more linear and less interdependent than varying individual curvatures. Therefore, CODE V automatically creates internal couplings among variable curvatures to take advantage of this. However, in some cases these default curvature variable couplings may result in slower convergence. This can typically occur for well-corrected systems, or for systems with many lens elements, such as refractive microlithographic systems. The command CVP Yes (command line only) can be used to disable the automatic curvature couplings. Note that although this is a command entered in the optimization (AUT) option, once set it remains in effect for the remainder of the current CODE V session until it is turned off using CVP No. This is true even if a new lens is restored in the current session.
Gaussian Quadrature Optimization
By default, CODE V optimization uses a rectilinear ray grid. This default ray grid works particularly well with systems that have obscurations, tilts and decenters, or are otherwise asymmetric, including asymmetric vignetting factors. However, for systems with circular or elliptical pupils, the Gaussian Quadrature (GQ) ray grid may lead to faster convergence. The total number of optimization cycles may be similar to when using a rectilinear grid, but GQ will trace a fewer number of rays so that each cycle is faster. When using GQ during optimization, the proper number of rings (NRR) and spikes (NSP) can be determined from the aberration content of the lens. For systems with nth order aberrations, where n = 2*m+1, GQ requires NRR > m+1.
The best way to visualize the GQ ray grid is to run the AUTOGRIDGQ.SEQ macro (Tools > Macro Manager > Sample Macros > Optimization). This macro also produces tabular output giving the ray radii and weights, as shown below.
For more details on these commands, as well as other optimization tips, please refer to the 2008 CODE V User Group Presentation "CODE V Advanced Optimization Techniques" on ORA's Customer Service Web site, www.oraservice.com.
CODE V Fall Training Classes at ORA
Limited space is still available in the Fall Spring 2008 CODE V Training Classes, to be held at ORA's Pasadena Headquarters.
- Introduction to CODE V: September 29 - October 3, 2008
- Advanced Topics in CODE V: October 6-10, 2008
To obtain more information about these courses, including a registration form, please follow the links under the Calendar section on the left side of this newsletter. |
