Optical Research Associates (ORA) has released Code V 9.81, which is the latest version of its optical design software.
New aspheric lens tolerancing capabilities, based on the work of ORA engineer Dr John Rogers, can be used with the Code V Fast Wavefront Differential Tolerancing (TOR) feature to tolerance surface errors that are easily measured in production using surface profilometry. These tolerancing capabilities will be especially valuable in the fabrication of optical elements that are either machined directly in metal or plastic, or, in high-volume production, created from mould inserts that are machined.
In addition, Code V’s ability to use measured interferograms of actual lenses has been improved. Specifically, the Fabrication Data analysis feature now provides a way to visualise interferogram data on a lens surface, entrance pupil, or exit pupil, including the ability to see rotation and scaling effects. This simplifies the correlation of measured lens surface deformations or wavefront perturbations with design data.
Code V 9.81 also delivers enhancements that address the demand for ever smaller features in the microlithographic production of semiconductor wafers. In particular, new software functions provide direct information about the critical dimension (CD) of the image, assuming a one-dimensional, partially coherent image, which is the standard design metric for microlithography. These functions, which have been added to the Partial Coherence analysis and TOR tolerancing features, will help designers learn how small variations in lens parameters affect the CD variation across the chip, assess compensation schemes given a specified tolerance, and understand how a full polarisation analysis affects process window computations.