We have opened a new INTERCONNECT simulation.
The configuration of the windows in the view is the same as what had set up in the earlier
in the layout editor navigation basics video.
The ring resonator circuit consists of waveguide couplers and straight waveguides.
To add a straight waveguide, go to the Element Library window.
You can either type in a keyword to search an element, or browse the folder structure
to find the element.
Click on the "Waveguides" folder to see the available models in the folder.
Click and drag the "Straight Waveguide" model over to the layout viewport.
In the Property View window, you can click on properties to modify their values.
Since we’ll have two straight waveguide elements, under the general properties I’ll
rename the element "Straight Waveguide1".
Now let’s assume that the ring has a radius of 40 micron which means that each of the
waveguides will have a length equal to 40 times pi microns.
By default, the units are in meters.
To change the units, you can click in the unit column and select micron.
Under the Standard properties, set the length to pi times 40 microns.
Under the Waveguide properties, you can see that there are two modes with orthogonal identifiers
1 and 2 to track two orthogonal modes of the waveguide labelled "TE", and "TM", which stand
for Transverse Electric and Transverse Magnetic.
We will focus on the TE mode in this example.
Set the effective index 1 value to 2.8 and the group index 1 value to 3.9.
Next, add a waveguide coupler element which can be found in the Couplers subfolder of
the Waveguides folder.
Set the name to "Waveguide Coupler1".
Under the Waveguide properties, if you click on the "input parameter" setting, it opens
a drop down menu that allows you to choose between specifying the coupling coefficient,
cross over length, or a table of coupling coefficients as a function of frequency.
We will set the coupling coefficient of Mode 1, which is the TE mode, to 0.2.
We can drag and drop another set of waveguide and coupler elements from the Element Library,
but a shortcut is to use duplicate the existing objects.
I can click on the waveguide and click the Duplicate button from the toolbar on the side
to create a copy, and do the same for the waveguide coupler.
Click and drag the elements in the view port to rearrange them.
Set the names of the elements to "Straight Waveguide2" and "Waveguide Coupler2".
Using the Rotate button in the toolbar, or the Ctrl+R keyboard shortcut, you can rotate
an element.
Rotate the straight waveguides so the ports are oriented vertically.
It’s also possible to disable any annotations that show up, for example, if I set the annotate
property of this waveguide to false, I no longer see the port and properties labels
for that element in the view port.
To connect the elements, I can use the mouse to click on the ports to connect.
If the "Auto-connect" setting in the Edit menu is enabled, I can also click and drag
an element, and hover one port over another and it will automatically add a connection
between two ports.
Next, add an Optical Network Analyzer (or ONA) from the Element Library.
In the standard settings, we will increase the frequency range to 1000 GHz to cover multiple
peaks in the ring’s transmission spectrum, and set the number of input ports to 2.
The ONA has one output port and can have multiple input ports.
The number of points is 1000 which is the number of frequency points measured over the
frequency range.
This should give a large enough resolution in the frequency domain to resolve all of
the peaks in the response.
Under the Waveguide settings, the orthogonal identifier is 1, which corresponds to the
TE mode.
This mode will be excited by the output port of the ONA when we run the simulation.
Connect the ONA output with port 1 of Waveguide Coupler1.
Connect port 3 of Waveguide Coupler1 to input 1 of the ONA.
This will measure the transmission straight through the input bus waveguide of the ring
resonator.
Connect port 2 of Waveguide Coupler2 to input 2 of the ONA.
This will measure the transmission spectrum of the light which couples into the ring and
then out through the drop port.
Before running, you can save the simulation file from the File menu.
In the next unit, we will run the simulation and plot the results.