Photon Engineering FRED, Paraxial Analyses

Paraxial Analyses

A common way to build an optical system in FRED is to import an optical prescription from CODEV^™, OSLO^™, or ZEMAX^™ prescription. FRED recognizes most surface types and apertures, and all of the coordinate system definitions found in these software. In almost all cases, the imported system will be faithfully reproduced in FRED.

However in order to verify the fidelity of the import, FRED has a paraxial analysis option. This feature organizes the surface information from a sequential path into a spreadsheet-like format that most optical engineers will instantly recognize: rows of radius, thickness to next surface, refractive media following the surface, and semi-aperture data. At the bottom of the dialog, the effective focal length and the locations of the front and back principal planes at user-specified wavelengths are displayed.

Additional diagnostics include:

•	System information including effective focal length, overall length, magnification, Lagrange invariant, Petzval curvature, working f/number, entrance and exit pupil diameters and locations, etc.
•	Paraxial raytraces of the marginal and chief rays
•	Third order surface and element contributions for the monochromatic aberrations

Paraxial layout for Houghton relay telescope

Paraxial raytrace for Houghton relay telescope