MSC Software and Sigmadyne Announce New Capabilities for Optimization of Optical Systems

MSC Software Corporation today announced that Sigmadyne, a finite element analysis consulting and software development company, has released extended capabilities for the analysis of optical systems using MSC Nastran as their primary simulation software.

Sigmadyne's latest release of SigFit™, an optical pre & post processor for MSC Nastran, allows optical response quantities to be written in MSC Nastran input format. This allows MSC Nastran's optimization capability to utilize optical behavior in the structural optimization of optical systems.

Optical performance is degraded by the distortion of reflective and refractive surfaces, and the characterization of such deformations is essential to performing optical performance evaluation. The best-fit polynomial characterizations of the predicted distortions of such optical surfaces can be generated by SigFit in the form of MSC Nastran multipoint constraint (MPC) equations. This feature allows engineers to characterize deformed optical surfaces within MSC Nastran using polynomial types commonly used in optical design. These equations now include enhancements to expand their usability to a wider array of applications involving significant lateral surface growth making them accurate for thermo-elastic load conditions.

Many modern telescopes include deformable mirrors to correct for unwanted optical surface figure errors induced by thermal or structural loading. A common design problem is to determine the optimum number and locations of the actuators required to correct these figure errors. MSC Nastran can be used to determine predictions of the disturbed optical surfaces and the influence functions for a large set of candidate actuator locations.

SigFit also provides many other options to use MSC Nastran in the analysis of optical systems. SigFit takes MSC Nastran analysis results and writes their effect in native formats for direct input to a variety of optical design programs. Examples include the temperature and stress changes in the index of refraction, including stress birefringence. The combination of MSC Nastran and SigFit provide a useful combination for the design of precision optical systems.

Dr. Victor Genberg, PE, President of Sigmadyne, stressed the key capabilities of MSC Nastran as instrumental in his business, "MSC Nastran is a great tool for multidisciplinary analysis because the analysis inputs and outputs are easily accessed. Execution of SigFit requires model geometry, displacements, temperatures and stresses for employment of its full array of optomechanical analysis types, and the simplicity in accessing this data from MSC Nastran streamlines the process of combining it with the power of SigFit."