Spherical aberration looks like this in a Transverse Ray Aberration (TRA) “ray fan” Spherical Aberration is characterized by a focus error that changes with – distance from the pupil center: For comparison, here is what pure focus error in a paraxial system looks like: Coma only affects off-axis fields it is a change in magnification with ray – distance from the center of the entrance pupil: Coma, in the ray fan plot, manifests as asymmetry in the Tangential TRA (in the Meridonal plane): (Note: The y-z plane is always the plane in Zemax, even though that “meridonal” is not the optical definition; Optically, the meridonal plane is the plane containing both the ray and the z-axis. The two definitions agree if rays are “meridonal” confined to the y-z axis.) Ray Pattern with Coma at the Paraxial Focal Plane: Using our Merit Function which reports 3rd order aberrations, we can write a Zemax macro (see: Programming Language”, chapter 25 in the Manual). “Zemax Here is a macro in the language that loops our system through 50 different “ZPL” Shape Factors and prints out the aberrations: !ThirdOrd.zpl ! !Print out 3rd order aberrations vs. shape factor !Run on Shape.zmx !Editors LDE and MFE must be open for macro to work correctly ! !Number of points to print: N = 50 ! !Surfaces in Shape.zmx frontsurf = 3 backsurf = 4 !Rows in MFE: Spha = 1
Spherical aberration looks like this in a Transverse Ray Aberration (TRA) “ray fan” – Spherical Aberration is characterized by a focus error that changes with distance from the pupil center: For comparison, here is what pure focus error in a paraxial system looks like: Coma only affects off-axis fields – it is a change in magnification with ray distance from the center of the entrance pupil: Coma, in the ray fan plot, manifests as asymmetry in the Tangential TRA (in the Meridonal plane): (Note: The y-z plane is always the “meridonal” plane in Zemax, even though that is not the optical definition; Optically, the meridonal plane is the plane containing both the ray and the z-axis. The two definitions agree if “meridonal” rays are confined to the y-z axis.) Ray Pattern with Coma at the Paraxial Focal Plane: Using our Merit Function which reports 3rd order aberrations, we can write a Zemax macro (see: “Zemax Programming Language”, chapter 25 in the Manual). Here is a macro in the “ZPL” language that loops our system through 50 different Shape Factors and prints out the aberrations: !ThirdOrd.zpl ! !Print out 3rd order aberrations vs. shape factor !Run on Shape.zmx !Editors LDE and MFE must be open for macro to work correctly ! !Number of points to print: N = 50 ! !Surfaces in Shape.zmx frontsurf = 3 backsurf = 4 !Rows in MFE: Spha = 1