Calendar

Introduction to CODE V
Oct. 29-Nov. 2, 2007
Pasadena, California
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Advanced Topics in CODE V November 5-9, 2007
Pasadena, California
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Quick Tip – Modeling Adaptive Optics in CODE V

Adaptive optics are frequently used in both astronomical and terrestrial applications in order to compensate for atmospheric turbulence.  Segmented or deformable mirror devices (DMDs) are often used to minimize the affects of the turbulence.  CODE V offers two different approaches for modeling DMDs via its non-sequential surface (NSS) capability and its user-defined surface (UDS) feature.  To simulate the atmospheric turbulence, CODE V interferogram files (INT) can be included in the lens model.

CODE V's non-sequential surface (NSS) capability can be used to model an array of rigid mirrors to simulate a DMD.  Each segment of the DMD allows for independent tip, tilt, and piston to be applied as needed.  CODE V's off-set tilt capability, introduced in version 9.60, can greatly facilitate the setup and repositioning of the individual mirror segments when using the NSS approach to model a DMD.

CODE V's user-defined surface (UDS) capability can be used to model a continuous deformable mirror.  The UDS approach bases its surface profile on actuator values and influence functions.  Sample FORTRAN and VISUAL C user-defined surface routines are supplied with CODE V.  These sample UDS routines, cv_uds_dmd.for and  cv_uds_dmd.c, are located in the UMR folder, directly beneath the main CODE V installation folder (i.e., C:\CODEV970\UMR).  These two pre-programmed UDS routines can be compiled and linked to your CODE V session (see CODE V Reference Manual, beginning on page 1-89 for more details).  In addition, a macro version of the DMD surface, uds_dmd.seq, is also supplied with CODE V and does not require a compiler.  However ray tracing the macro version will take substantially longer than ray tracing the compiled versions of the UDS.

There are several additional resources for modeling DMD's available on CODE V's Customer Service Web Site, www.oraservice.com.  These include a technical paper, "Using CODE V to Model Adaptive Optics", a slide show summary of the paper, example files of models presented in the paper, and a macro for creating an INT file to simulate atmospheric turbulence using Kolmogorov statistics.  A copy of this technical paper and associated files can be found under CODE V Support > Technical Papers.

Updates to ORA's Customer Service Web Site

The following additions have been recently made to ORA's Customer Service area of the web, www.oraservice.com , under CODE V Support:

• The August issue of CODE V Enews, which featured a tip on finding the most effective compensators for tolerancing and alignment via singular value decomposition (SVD), has been added under CODE V Enews & Tips. A related presentation from the 2007 CODE V User Group meetings can also be found under User Group Presentations.
  
  
• An updated version of the macro, CVTFIELD, has been added under Macros and User-Defined Downloads > Updated Macros. This macro, supplied with CODE V, is used for converting field type specification (i.e., field angles to image heights, etc.). The updated version properly handles zoomed fields.
  
  
• The technical paper referenced in the preceding tip, "Using CODE V to Model Adaptive Optics", along with example files and associated macros, has been added under Technical Papers.