Source power can be apodized from a rectilinear grid of amplitude/phase data, which can either be entered manually, applied using a bitmap or imported from formatted text file
This feature can be accessedby selecting Amplitude/Phase Mask on Rectilinear Grid as the Position Apodization type on the Power tab of a Detailed Source dialog box.
The following controls are available by right mouse clicking in the Amplitude/Phase Mask spreadsheet area.
The Sampling Array Size should match the X- and Y-Semi-Ape as set on the Source Position/Direction Tab. Take into account the dimensions of the bitmap as well.
The spatial sampling of a Grid should be consistent with sampling required to accurately reproduce the amplitude/phase mask. In the case of coherent sources, be aware that spatial sampling is limited to about 10l due to the paraxial condition imposed on the individual gaussian beamlets (q < 0.01).
When a bitmap is imported into the amplitude/phase mask the following conversion formula is applied to the R,G,B color components to achieve the resulting pixel value, P: P = (0.30R + 0.59G + 0.11B)/255
Positional Apodization can be read in as a formatted text file or as an FGD file by right mouse clicking in the spreadsheet area and selecting either "Replace Data with File Data" or "Replace Data with data from FGD File". For information on the *.FGD file format, please see this help topic.
Text File Formatting When using the text file format option, there must be two header lines followed by the grid of data. The first header line is written as:
type position_apodization
The second header line is the word "format" followed by two keywords and two values defining the semi-aperture of the grid data. The first key word can be either "power", "amplitude", or "real" and the second keyword can be "waves", "OPL", "degrees", "radians" or "imaginary". The semi apertures are floating point values. For example, if the grid data being provided in the text file is to be interpreted as "power" and "waves" with grid semi-apertures of 1.234 and 5.678 in X and Y, the second header line would be written as:
format power waves 1.234 5.678
The grid data comes in value pairs, with a minimum grid size of 2 x 2 pairs. The number of X samples in the grid is determined from the first row of data pairs, with each pair counting for one sample. The number of Y samples is determined by the number of rows in the grid data. If the number of X samples in a given row is more or less than the number of samples in the first row, the sample values will either be truncated or padded with zeros to form a rectangular grid. The sample grid below demonstrates a 3 x 4 grid:
0.5 0 0.75 0 0.5 0 0.75 0 0.95 0 0.75 0 0.75 0 0.95 0 0.75 0 0.5 0 0.75 0 0.5 0
Some examples of the text file format for the position apodization specification are provided below.
Position Apodization - R^n distance apodization Position Apodization - Gaussian apodization Position Apodization - Uniform Unit Apodization Amplitude/Phase Mask - Modify Cell Values Amplitude / Phase Mask - Set Sampling Array Size
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