Measure reference#

Measures are available through PyMieSim.Measure or their historical string names. For example, Measure.QSCA and "Qsca" are equivalent.

Efficiencies and dimensionless quantities#

Name

Meaning

Unit

Geometries

Qsca

Scattering efficiency

dimensionless

sphere, cylinder, core–shell

Qext

Extinction efficiency

dimensionless

sphere, cylinder, core–shell

Qabs

Absorption efficiency

dimensionless

sphere, cylinder, core–shell

Qback

Back-scattering efficiency

dimensionless

sphere, cylinder, core–shell

Qforward

Forward-scattering efficiency

dimensionless

sphere, cylinder, core–shell

Qratio

Back-scattering-to-scattering ratio

dimensionless

sphere, cylinder, core–shell

Qpr

Radiation-pressure efficiency

dimensionless

sphere, cylinder, core–shell

g

Anisotropy factor

dimensionless

sphere, cylinder, core–shell

g_with_farfields

Anisotropy factor evaluated from sampled far fields

dimensionless

single-particle API

size_parameter

Dimensionless size parameter

dimensionless

sphere, cylinder, core–shell

Cross sections#

Csca, Cext, Cabs, Cback, Cforward, Cratio, Cpr, and cross_section are area-valued measures in square metres. Results are returned as unit-aware quantities in single simulations and as numerical columns with unit metadata in experiment DataFrames.

Coefficient measures#

The experiment API also exposes the first few Mie coefficients (a1, a2, a3, b1, b2, and b3) where supported by the configured scatterer. These are dimensionless complex coefficients and are primarily useful for diagnostics and theory comparisons.

Detector measures#

coupling is collected optical power and has units of watts. It is only available when a detector is configured. The detector type, angular sampling, polarization filter, and coherent/non-coherent mode determine its exact meaning. See Detector coupling.

Discoverability#

Use the configured object rather than guessing which measures are valid:

simulation.available_measures
experiment.available_measures

An invalid request produces an error listing the available names for the current geometry and detector configuration.