Photonic Solutions Enewsletter

Quick Tip: Using OptSim Circuit and OptoDesigner for Electrical Autorouting

When designing photonic integrated circuits (PICs), there is often a need for active components that require electrical connections in addition to optical waveguides. With the introduction of the PIC Design Suite version 2019.09, OptoDesigner is now able to generate electrical ports and automated electrical routes when driven from OptSim Circuit with the bi-directional interface. This capability was supported in previous versions of the software for optical waveguides and works in a similar way for electrical connections. The main difference is that the composite elements (such as bends, straights, and vias) that define electrical routes are not stored as individual components in the shared design file.

In most PDKs provided by our foundry partners, the electrical autorouter is preset to route on two metal layers. One layer is used for horizontal routing and the other is used for vertical routing. When a route needs to go from the horizontal layer to the vertical layer, a via is automatically placed to connect the two layers completing the connectivity.

RSoft Photonic Device Tools Feature Highlight: Polarization Analysis Plots

Because of the vectorial nature of light, most photonic devices are polarization sensitive. Version 2019.09 of the RSoft Photonic Device Tools includes a new feature that accurately analyzes a device’s polarization state by displaying the spatial variance in the polarization ellipse. You can access the feature with the complex vector option in WinPLOT: /vectc. Polarization analysis requires two 2D complex data profiles and displays the polarization ellipse within the plot.

As an example, we take the Q-plate for orbital angular momentum to show how a right-handed-polarization (RHP) Gaussian beam is converted into left-handed-polarization (LHP). The Q plate example is described in detail in this application note.

Figure 1(a) shows the nylon Q-plate with carved ring grooves on both sides of a disc [1]. A circularly RHP Gaussian beam is incident on it, as shown in Figure 1(b). With a full vectorial (3D) FullWAVE FDTD simulation, the complex Ex and Ey fields are recorded at different positions along the propagation direction (Z). The polarization plot and its magnitude at the end of the 10 mm thick disc is shown in Figure 1(c).