I want to perform the overlap integral of the OSLO coupling efficiency calculation on a more complex mode structure than a fibre,

so I would like to output the amplitude and phase of the point spread function to a file. The PSF is calculated using an FFT, so basically I would like to output the entire FFT array to a file. How can I do this?

Synopsis

Computing the coupling efficiency of a complex waveguide

Solution

"Please note that in the Computer Fiber Coupling Efficiency dialog box (Choose ""Source>>Fiber coupling..."" from the OSLO menu), you can specify a complex waveguide mode type by using a CCL command that describes a user-defined mode [this option is only available in OSLO Premium - see "Evaluation>>Beams/Fiber Coupling>>Fiber Coupling" on the "Contents" tab of the OSLO online help system] However, if you still want to compute the overlap integral yourself, you must export the FFT array to a file as you indicated:

• The graphical PSF analysis uses an OSLO internal routine that calculates the FFT and plots the PSF directly to the screen. The FFT data cannot be accessed by the user, so this approach is not an option.
• In OSLO Premium, the "fpa" command calculates and prints the FFT data (amplitude and phase) to the text window. Once the data is in the text window, you can cut and paste it into an external file (such as an Excel spreadsheet), or if you wanted to automate the process, you could write a CCL routine that moves the FFT data directly to an external file.

Note: The "fpa" command is not available in OSLO Standard, Light, or EDU"