SpheroFront

This software is made available for download and use under the Creative Commons License license.

What is It?

SpheroFront allows analysis of diffraction in focusing optics and can be used to evaluate the impact of aperture obstructions on the point spread function at and near the focal point in systems ranging from microscopes to telescopes.


SpheroFront features:

  • Support for arbitrary aperture masks
  • Sensible defaults for angular spectrum sampling and tile summation
  • Adjustment of output field size and sampling pitch independent of the input field
  • Perceptual rendering under scotopic and photopic vision assumptions
  • Control of illuminant colour temperature
  • Togglable auto-calculation for interactive use
  • Memory requirement estimation
  • Intermediate result caching for rapid evaluation of defocus fields

Overview of the SpheroFront graphical user interface

SpheroFront interface.

The underlying library is open source and implements the summed field method, a modification of the angular spectrum method, proposed by Hillenbrand et al. The summed field method allows for memory efficient evaluation of apertures with large Nyquist sampling requirements in systems where the power of the output field is concentrated in a relatively small area. The use of the 1st Rayleigh-Sommerfeld diffraction integral provides significant improvements in off-axis accuracy when compared to the simpler and computationally cheaper Fresnel diffraction approximation.

SpheroFront Samples


True color Bahtinov diffraction pattern showing characteristic misalignment when defocused

Bahtinov Diffraction Grating - 500µm defocus - Photopic.
True color airy disk

Airy Disk - Photopic.
True color point spread function of the James Webb Space Telescope

JWST - Visual Wavelengths - Photopic.
Narrowband intensity point spread function of the James Webb Space Telescope rendered in the inferno colormap

JWST - Narrowband Intensity - Inferno Colourmap.