Gaussian Beam Calculator for Creating Coherent Sources

Coherent sources are represented in FRED using a superposition of Gaussian beamlets. The ray grid spacing of the source is used to determine the waist and divergence of the beamlets. To properly model coherent propagation properties, the beamlets must remain Gaussian and perform best when they obey the paraxial approximation. As a result, some Gaussian beam calculations should be performed to determine the appropriate grid size and number of rays for a coherent source. The attached script uses desired source parameters to calculate and display the proper inputs for a new coherent source. This calculator is valid for the following source types:

Simplified Source

  • Collimated Source (plane wave)
  • Laser Beam (Gaussian 00 mode)

Detailed Source

  • Grid Plane (rectangular array of points arranged on a plane)
  • Hexagonal Plane (hexagonal array of points arranged on a plane)

Gaussian beam calculator dialog

Gaussian Beam Calculator PDF

Download the FRED script GBCalculator.frs