PIC Design Suite Transparent Components

Introduction

When designing photonic circuits, it might not always be known in which technology the circuit will be fabricated. Also, it is useful to be able to create a circuit design and evaluate the performance and cost in different technologies. To be able to do so, the design must be made in such a way that different foundries that supply different technologies can read the same design and implement their technology on that specific element. ��ϲ�ֱ�� provides the unique technology-agnostic library to create a design: px-elements. Many foundries that have ��ϲ�ֱ�� compatible PDK��s support this technology and implement px-elements for their own technology.

px-elements are generalized building blocks for mapping technology-agnostic components to technology specific components. Technology specific designs can be created directly using the foundry building blocks, but this makes it hard to transfer designs and thus leads to supplier lock-in. This is not always desirable. Using px-elements is a big improvement, since the design can be exported to another foundry with little effort.

This feature highlight demonstrates an example where different technologies are used to implement the same component. This layout uses generalized px-elements.

To access the px-elements, load the User Framework ``@layout`` in script. The available px-elements can then be found in the Element tab, under ��User lib �� PDA-BB."

Example: MZI

Demonstrating how the same layout gets interpreted by 3 different technologies, we are using the same script but will be using toggling different technologies: TowerJazz, AIM Academy, and DemoFab (the technology included with OptoDesigner in the ��ϲ�ֱ�� PIC Design Suite).

First the MZI layout is defined. This is done by using only px-elements. For this layout example, we are using several standardized px-elements.

Generic Building Block	Fab Specific mapping (example DemoFab)
pxMMI2x2	demofabMMI2x2
pxStraight	demofabStraight
pxFCI	demofabFiberCoupler
pxFCO	demofabFiberCoupler

After this the MZI and fiber couplers are placed. Furthermore, we also use the following for routing the connections, which create connectors between multiple ports that consist of 90-degree arcs and straight waveguides.

- pxManhattan_Nports

The only thing adjusted between the different layouts is which foundry has been enabled; this command line is found at the beginning of the script layout.

- pda::enableFoundry ("APSUNY.ED");

- pda::enableFoundry ("TOWERJAZZ");

- pda::enableFoundry ("DEMOFAB.SOI");

The layout resulting of the MZI in each foundry is shown below.

AIM Academy

TowerJazz

Demofab

Summary

In this feature highlight, we considered a feature designed to improve the development cycle for users of ��ϲ�ֱ�� tools. We showed that by using generalized and technology-agnostic px-elements, a design can be made that can be used with numerous technologies without having to adjust the script.

For more information and to request a demo, please contact photonics_support@synopsys.com.

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