Diffracting 2D Gaussian Beam.

optoex16.in : Diffracting 2D Gaussian Beam.

Requires: S-Pisces/Luminous
Minimum Versions: Atlas 5.28.1.R

This example demonstrates:

  • Diffraction of a spatially confined beam

This example shows an added capability of Luminous to describe diffraction in 2D. The input deck of this example is identical to that of optoex10.in except for the bpm parameter in the BEAM statement. This parameter specifies that the beam propagation method be used by Luminous instead of ray tracing. This is equivalent to using the wave optics approach instead of geometrical optics. The effects of optical wave diffraction and interference are automatically taken into account when the beam propagation method is used.

Diffraction effects of a Gaussian beam propagating in silicon is shown in this particular example.

Other parameters that can be specified in the beam statement for the beam propagation method are longit.step and transv.step . These parameters are used to set respective step sizes for the internal bpm grid. When the step sizes are not defined explicitly, the default values are used. The default step size in both directions is equal to wavelength/16.0. It is emphatically not recommended to use step sizes larger than wavelength/2.0, especially if coherent effects are of interest. The user is also cautioned against use of extremely small step sizes as they can result in unnecessarily long computation times. Default values provide for adequate treatment in most cases.

Some parameters specific for the ray tracing are ignored in the beam propagation method. For details, see BEAM statement in the Atlas manual.

To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the Run button in DeckBuild to execute the example.