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Summer Short Course Series

Opto-Mechanical Lab

2020 Course Description

Please note: The course descriptions and instructors listed below are NOT final, it is possible that circumstances beyond our control could necessitate alterations.

June 10-12, Wednesday through Friday

Greg Michels (Sigmadyne)

This course will be taught in a computer lab to illustrate the use of SigFit to solve a variety of optomechanical problems. The focus of the material will be the use of SigFit to run various types of analyses as illustrated in the example problem descriptions below. With most of the emphasis of the course placed on the use of SigFit, significantly less emphasis will be on the theory behind optomechanical analysis and finite element modeling of optical systems. This lab course is directed at engineers who have taken the optomechanical analysis course or who have background in the field. Students will learn the use of SigFit through alternating projected presentations and hands-on example problems with interactive instructor oversight.

Example problems will include:

  1. Characterization of Surface Deformation and Rigid Body Motion—Zernike or other polynomials will be fit to finite element deformations and the results will be written for import into optical analysis models. Issues of normalization, sag vs normal deformation, and residual error will be addressed. Output formats, results plotting, and program options are demonstrated.
  2. Analysis of Active Optics—Simulation of surface error correction for active mirrors will be covered. Inclusion of active control design issues such as stroke limits and actuator placement are discussed.
  3. Line-of-Sight (LOS) Calculations—An example telescope model is used with Sigfitto calculate LOS coefficients and LOS disturbance due to static loads.  For a random base shake, the LOS jitter is calculated and the contribution from each dynamic mode is determined.
  4. Thermo-Optic and Stress-Optic Analysis—The effect of optical index change of a lens assembly due to temperature gradients and stress are calculated and passed to an optical analysis model.  The calculation of stress birefringence is also demonstrated.
  5. Optomechanical Tolerance Analysis—A variational analysis using Monte Carlo techniques is performed to quantify the statistics of optical performance due to mechanical mounting tolerances of an optic.
  6. Analysis with an Offset Aperture—Polynomials are fit to the surface deformation of an optic with an offset aperture. Issues such as limitations in importing results to optical analysis are covered.
  7. Analysis of Diffractive Optics—Characterization of mechanically induced changes in phase of diffractive optics such as linear gratings and phase surfaces is covered. Import of such characterization to optical models is covered.