Beams

As mentioned in the Rays section, a beam within the context of this package serves as a data structure for storing collections of rays, forming the backbone of the simulation framework. A beam splits into child beams, e.g. at a beamsplitter, and solve_system! traces it together with all its children. Browse the catalog below, or refer to the table of contents for detailed documentation of the provided beam types and sources.

Beam catalog

Beams, beamlets and beam groups are traced through a bi-convex lens onto a detector near its focus.

Ray

Monochromatic geometrical ray with position and direction.

Rays

PolarizedRay

Ray that carries a complex electric field vector.

Rays

Beam

Tree of rays that stores a light path, including split beams.

Beams

GaussianBeamlet

Stigmatic Gaussian beam traced via chief, waist and divergence rays.

Beamlets

AstigmaticGaussianBeamlet

Polarized Gaussian beam with independent waists in two axes.

Beamlets

CollimatedSource

Parallel beams on concentric rings, i.e. a plane wavefront.

Beam groups

UniformDiscSource

Collimated source with equal-area Fibonacci sampling.

Beam groups

PointSource

Cone of beams from a single point, i.e. a spherical wavefront.

Beam groups

UniformPointSource

Point source with an equal solid angle per ray.

Beam groups

UniformLineSource

Plane sheet of parallel beams on a line, incl. marginal rays.

Beam groups

UniformFanSource

Plane fan of beams from a single point, incl. marginal rays.

Beam groups

AstigmaticBeamGroup

Container for a coherent group of astigmatic Gaussian beamlets.

Beam groups

CollimatedGaussianBeamletSource

Square grid of beamlets forming a flat-top plane wave.

Beam groups

GaussianBeamletDecomposition

Large Gaussian beam decomposed into a grid of beamlets.

Beam groups

SphericalGaussianBeamletSource

Spherical wave decomposed into a cone of beamlets.

Beam groups

EllipticalGaussianBeamletSource

Beamlets on an elliptical cap, e.g. for laser diodes.

Beam groups

WavefrontBeamletDecomposition

Measured or custom complex field decomposed into beamlets.

Beam groups

Beam overview

• Basic beam
  • Inspecting a traced beam
• Gaussian beamlet
  • Complex ray tracing
  • Stigmatic beamlets
• Astigmatic polarized beamlets
  • Formalism
  • Astigmatic beamlets
  • The Curvature Matrix Q
  • Physical Beam Cross Section
• Beam groups
  • Collimated beam source
  • Point beam source
  • Line and fan sources
  • Sampling and number of rays
  • Astigmatic Beam Groups

Beam models

The beamlets are traced as several Beams of rays side by side:

A beamlet stops when its rays hit different shapes, when only some of its rays hit anything (a partly clipped beamlet), when the interact3d method of the object returns nothing, or when its invariant check fails. The tracing loop and the interface of a beam type are described in Tracing a beamlet and Beam interface.

Moving beams

Rays, beams and beam groups can be moved with the same kinematic API as optical elements, see Moving sources in the Kinematics section.