VPItoolkit™ PDK HHI - Overview

VPItoolkit PDK HHI is a pluggable toolkit to VPIcomponentMaker Photonic Circuits which supports InP photonics Process Design Kit (PDK) for Multi Project Wafer (MPW) runs offered by the Fraunhofer HHI.

The toolkit provides a library of photonic devices (see figure below) which covers most of the building blocks (BBs) currently supported by the HHI Process Design Kit. Each BB is characterized by only a few user-defined parameters and is modeled with an adequate simulation model, elaborated in collaboration with the Fraunhofer HHI and members of the PDAFlow Foundation. This allows a designer to rapidly prototype application-specific photonic integrated circuits (ASPICs) with prerequisite functionality without going deep into the details of device layout and fabrication process.

VPItoolkit PDK HHI supports the PDAFlow application programming interface (API) designed to link different photonic simulation and design automation tools. Once the ASPIC design is completed and optimized, its layout can be exported to PhoeniX OptoDesigner for adding packaging and waveguides/wires routing. Then the GDSII mask layout can be exported and sent to the foundry for fabrication.

As a result, VPItoolkit PDK HHI enables fast designing of InP-based monolithically integrated photonic circuits for their subsequent fabrication at the Fraunhofer HHI foundry.

The design flow and integration between VPIphotonics tools and PhoeniX OptoDesigner can be illustrated as follows:

VPItoolkit PDK HHI - BBs list

Overview of building blocks available in VPItoolkit PDK HHI

VPItoolkit PDK HHI - PIC Design

Integrated design flow for photonic circuits


  • Prototyping integrated active and passive InP-based photonic integrated circuits with prerequisite functionality

  • Optimization of the designed circuit using standard VPIcomponentMaker Photonic Circuits instrumentation

  • Fabrication tolerance and yield analysis


  • Library includes most of the passive and active BBs which can currently be fabricated at the Fraunhofer HHI foundry

  • Adequate simulation models of the BBs based on characterization data from the Fraunhofer HHI

  • Automated export of circuit to PhoeniX OptoDesigner for layout packaging and GDSII mask generation

  • Support of PDAflow API

  • Seamless integration into VPIcomponentMaker Photonic Circuits

Integration in VPIcomponentMaker Photonic Circuits

All the building blocks supported by VPItoolkit PDK HHI can be used alongside with a broad set of standard modules and instrumentation in VPIcomponentMaker Photonic Circuits.

VPItoolkit PDK HHI - Integration

Advanced libraries of standard modules, including:

  • Passive and active components with thoroughly tested and extensively documented physical models

  • Optical and electrical signal sources

  • Open interface for experimentally measured or numerically calculated device models

Flexible design and modeling capabilities, including:

  • Unique hybrid time-and-frequency-domain modeling (TFDM) approach for large-scale active photonic integrated circuits

  • Hierarchical design approach

  • Python, Matlab and C++ cosimulation

Design Examples

Transmitter and Receiver PIC for THz applications

Flat-top filter based on ring-loaded unbalanced MZI structure


See the video below for more details about how to export a circuit designed with VPItoolkit PDK HHI into PhoeniX OptoDesigner.

See the video below for more details about how to design photonic integrated circuits with VPIcomponentMaker Photonic Circuits.