文档介绍:Opto-Mechanical I/F for ANSYS
Victor Genberg, Gregory Michels, Keith Doyle
Sigmadyne, Inc.
Abstract
Thermal and structural output from ANSYS is not in a form useful for optical analysis software.
Temperatures, displacements and stresses at arbitrarily located FE nodes can not be input directly into
optical software. This paper discusses the post-processing steps required to present ANSYS results in a
useable format for CODEV, ZEMAX, and OSLO. Specific issues include optical surface deformations,
thermo-optic effects, adaptive optics, and dynamic response. Finite puted optical surface
deformations are fit to several polynomial types including Zernikes, aspheric, and XY polynomials. Higher
frequency deformations are interpolated to a user-defined uniform grid array using element shape functions
to create interferogram files. Three-dimensional shape function interpolation is used to create OPD maps
due to thermo-optic effects (dn/dT), which are subsequently fit to polynomials and/or interferogram files.
Similar techniques are also used for stress birefringence effects. Adaptive optics uses influence functions to
minimize surface error before or after pointing and focus correction.
Introduction
High performance optical systems require integrated optomechanical analysis to predict performance
(Reference 1). This requires that finite element analysis (FEA) results be accurately passed to optical
analysis programs (see Figure 1). Optical analysis programs have very limited input formats. Rigid body
motions of optics are input using one file format, whereas elastic distortions are typically described as
Zernike polynomials or rectangular arrays in a separate file.
Figure 1. Integrated Analysis
Zernike polynomials are an infinite set of polynomials (see Figure 2) of radius raised to a power (N)
multiplying sines and cosines of multiples (M) of polar angle. The terms N and M are referred to as the
radial and circumferential