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Using the energy capture plot

The energy capture plot displays a graph of energy captured from an isotropic point source as a function of the position of the point source in the field of view. This is a purely geometrical calculation, and does not take into account energy losses in the lens due to reflections, scattering, or absorption.

The energy capture plot is presently only available for finite-conjugate systems (i.e., with the object surface a finite distance from the lens).

To create the energy capture plot window:

  1. Select from the menu Analysis > Energy > Capture

Exporting data from energy capture plot

The underlying data may be exported using the Export toolbar icon, or by "Save data as..." on the contextual menu (obtained by control clicking on the image).

Options panel

Search
Using the Search popup menu, select the type of search to be performed. Presently the only option is "Spherical octahedron", which uses a recursive spherical triangulation, starting from a spherical octahedron, to search the entire forward half of the emission sphere of an isotropic emitter to determine the solid angle into which emitted energy passes through the lens to the indicated surface.
Recursion depth
During the search, spherical triangles are subdivided where they straddle the boundary between captured and lost energy. The recursion depth parameter is the number of subdivisions. Typically 7 will yield a good result. The gap between the "maximum" and "minimum" dashed curves on the plot indicates the uncertainty associated with the finite search depth.
Wave
Using the Wave popup menu, select the wave for which you wish to calculate.
Field scan type
The type of scan to be performed in the field of view. Presently the only option is "Y Line", which is a scan with x=0 and y ranging over the full range specified in the Field table.
Field scan number of points
Number of points in the field of view at which the captured energy will be calculated. The calculation time is proportional to this number. Keep in mind that spline smoothing may be used to make a smooth curve from just a few points.
Surface
The surface popup allows you to select a surface that rays much reach to be considered "captured".
Quantity to plot
Transforms the raw data to various representations, such as solid angle, fraction of sphere, fraction of hemisphere, or numerical aperture.
Abscissa
Quantity to use for the horizontal axis of the plot. Presently the "Field Y" variable.
Ordinate
How to display the captured energy. Transforms the raw data to various representations. For finite conjugate system, the options are solid angle, fraction of sphere, fraction of hemisphere, or numerical aperture.
Color by
Use this popup to indicate how curves will be colored.
Paraxial trace
If checked, all rays will be traced paraxially. Only useful for diagnostic purposes.
Scale only expands
If checked, the scale of the axes only expands due to the action of sliders, etc.
Axis tight on data
If checked, the limits of the axes are chosen so that the data exactly fills the graph. If not checked the limits of the axes are chosen to give "nice" values at the extremes of the axes.
Spline smoothing
If checked, spline interpolation is used to give smoother looking curves.

See also