# Release notes IPKISS Photonics Design Platform 3.5.0¶

The IPKISS 3.5 Photonics Design Platform now comes with the “IPKISS AWG Designer” preinstalled (formerly known as “Filter Toolbox: AWG Designer”). In this release, several improvements and changes have been made to make it easier to design Arrayed Waveguide Gratings (AWGs). In addition, new layout operations are introduced that make it easier to build DRC-clean photonic integrated circuits (PICs). Several other improvements are made to the performance and layout correctness (shape cutting for layouts which have holes) and to our CAMFR integration (calculating 1D modes and improved simulation accuracy).

A full list of improvements can be found in the changelog.

Highlights are shown below:

## IPKISS AWG Designer¶

The “IPKISS AWG Designer” is the new name for the product formerly known as “Filter Toolbox: AWG Designer”.

In this release we have made several changes that make it easier to create AWGs for a variety of technology platforms and to implement various form factors. Documentation is available in the form of an API reference, samples, guides and extensive tutorials.

The workflow for creating AWGs remains the same: the user starts from high-level specifications of the AWG, performs synthesis (specs -> layout parameters), builds the design in layout, then runs simulations to verify the correctness, and finally prepares the AWG for tape-out. This step-by-step process is now made easier and is clearly explained in a tutorial on Luceda Academy.

### Note on backward compatibility¶

Most of the functionalities should be backward compatible with previous releases, except for the import statement (‘filter_tb’ is renamed to ‘awg_designer’). Slight changes in the generated AWG might be observed due to more accurate CAMFR simulations, which have an impact on the spreading angle into the star coupler.

Some of these improvements could not be made without some changes to the way apertures are drawn and the way AWGs are composed. The porting guide can help you on your way to convert your current AWG projects from IPKISS <= 3.4 to IPKISS 3.5. Should you have any questions don’t hesitate to contact us at support at lucedaphotonics.com.

## Layout improvements¶

Several utility functions have been added that help designers create DRC-clean devices. All layout manipulations that are now available in IPKISS are documented in one place, so it is easier to learn what are the possibilities for doing boolean operations, merging shapes, detecting and patching sharp angles, etc.

In addition, we have improved our shape cutting algorithm that works when generating the polygons for shapes that have holes in them (which is not supported by GDS and requires a conversion). The new algorithm is now correct and does not generate new points (which could lead to DRC and/or snapping errors). They are also significantly faster.

## CAMFR improvements¶

The integration between IPKISS and CAMFR has been improved.

• There is now a function i3.device_sim.camfr_guided_modes to calculate the guided modes and a function i3.device_ism.camfr_mode_fields to calculate the fields. Given that each IPKISS PDK comes with predefined virtual fabrication, this makes it easy to calculate the modes and fields for your foundry of choice. New functions are documented in the device simulation API reference.
• The discretization of the CAMFR engine has been improved and made more accurate. Rectangular shapes are now represented exactly instead of being discretized. Also the resulted discretized structures are symmetrical if the input was symmetrical. A tutorial has been added to get started with CAMFR simulations in IPKISS.