Paraxial

This section provides an overview of the paraxial optics module in Optiland. This module enables the user to perform paraxial analysis of the optical system.

Conventions

Location quantities follow Optiland’s reference-surface convention, where object-space quantities are measured relative to the first physical surface (index 1) and image-space quantities relative to the image surface:

  • EPL() (entrance pupil location) is relative to the first physical surface (surface 1).

  • XPL() (exit pupil location) is relative to the image surface.

  • The focal, principal, nodal, and anti-nodal planes (F1/F2, P1/P2, N1/N2, P1anti/P2anti, N1anti/N2anti) follow the same per-surface convention, where 1 denotes object space and 2 denotes image space.

When a global z coordinate is needed for the entrance pupil — for instance to compare it against object or surface positions — use entrance_pupil_z(), which converts EPL() to the global frame in one place. Internally, every ray-aiming, ray-tracing, and aperture consumer that mixes the pupil location with global coordinates routes through this helper.

paraxial

Paraxial Module