        Cross-Couplers
        ---------------

This project consists of one waveguide which has been positioned above another. 
This is easily seen by pressing the toggle plan/side view button on the toolbar.

At the centre of the FIMMPROP component, the two waveguides cross each other.
Note that these waveguides are buried waveguides and so this is a fully 3D
problem. 

This problem was easy to setup using the taper component with mwg waveguides. 
1. We simply defined the left-hand side cross-section using an mwg.
2. Copied this mwg to a different file, renamed it 
3. Using FIMMWAVE, clicked on the waveguide cores in the MWG window, and draged it to the position required for    
   the waveguide core on the right hand side of the device!!!!


This problem can now be solved with relative ease.

* Open the project
* Select the crosscouplers component
* Click on the "View Optical Field Icon".

On an 800 MHz machine, after about 40 minutes, a field plot will be displayed showing that a quarter 
of the input power entering the lowermost core is coupled into the lowermost core on the right hand 
side of the device.
