Название: Introduction to Layout Design and Automation of Photonic Integrated Circuits
Автор: Ahmadreza Farsaei
Издательство: Springer
Серия: Synthesis Lectures on Digital Circuits & Systems
Год: 2023
Язык: английский
Формат: pdf (true), epub
Размер: 33.5 MB

This book introduces readers to the physical design (layout) and design automation of Photonic Integrated Ciruicts (PICs) which is an essential building block of Electronic-Photonic Design Automation (EPDA). Proper PIC design automation and implementation of complex curvilinear shapes play a critical role in reliability, quality, and time-to-market of complex PIC products. The author starts by introducing some basic mathematical concepts used in implementation of photonic components, followed by a deep dive into implementation details of parameterized PIC components. The book introduces the industry-standard schematic driven layout flow and tries to simplify the concepts and implementations. The author conveys difficult concepts and advanced EPDA scripting/programming methodologies, using a simple language and coding examples.

Silicon photonics is a promising platform and technology whose application covers not only high-speed communication links used in data centers, but also novel applications in biological sensing, Light Detection and Ranging (LiDAR), and co-packed optics. The design complexity of Photonic Integrated Circuits (PICs) supporting these applications has been significantly increased both in terms of architecture and the number of device instances used to create the final mask layout. PIC designs’ evolving complexity requires a unified and salable design automation solution to address their unique challenges. Although there have been many textbooks on fundamental concepts and basic physics of silicon photonics, there is not a body of literature providing proper education on PIC design automation.

There are three main challenges that an Electronic Photonic Design Automation (EPDA) solution should address: (1) Implementation of photonic components’ complex curvilinear shapes, (2) Enabling a unified electro-optical co-simulation flow, (3) Native support for physical verification and extraction of complex curvilinear shapes. In this book, I am mainly focused on the implementation of complex photonic components’ curvilinear shapes. Traditional Electronic Design Automation (EDA) solutions are based on supporting rectilinear/octilinear concepts. This implies that these solutions are not capable of reliably supporting complex curvilinear shapes required to implement a photonic component’s mask layout. Proper implementation of an EPDA solution should be derived from an EDA solution with an additional mathematical engine to: (1) Capture curvilinear shapes using parametric mathematical equations, (2) Manipulate curves and extract curves’ characteristics, (3) provide required software constructs to represent a photonic device using parametric mathematical equations, and (4) establish a link between mathematical domain and discretized polygon domain for the final generation of mask layout.

The book comprises six chapters that are structured to be very concise, practical, and example-driven. The content of each chapter is chosen carefully and is based on the training I have had for professional and industry experts. Each chapter starts with a main concept and continues with code examples and use cases to support that concept. Each chapter is written in such a way that you should be able to read and comprehend the main concept, and write and test code examples in a day. I have included some exercises inside each chapter so that you can evaluate your progress and understanding of the concepts.

Chapters 1–3 are mainly focused on photonic devices’ physical implementation and introduction to Virtuoso® CurvyCoreTM Application Programming Interfaces (APIs). Chapter 4 is focused on the Parameterized Cell (PCell) concept and implementation as well as some fundamental concepts behind a hierarchical design methodology such as terminals, pins, instance terminals, etc. Chapter 5 is focused on how to solve some design problems by SKILL scripting. I have included Chap. 6 to introduce proper scalable software development methodology using SKILL++. Virtuoso is the tool used for the implementation of my designs and the Virtuoso CurvyCore mathematical engine is used to implement photonic devices’ physical design (layout). SKILL is the main scripting language used for code implementation. All the examples provided in the book are based on Generic Optical Process Design Kit (GoPDK), which is a generic optical PDK developed by Cadence Design Systems, Inc. to demonstrate their photonic solution capabilities.

In this book, I have assumed you have basic knowledge of algorithm, software development, data structures, and SKILL programming. Although deep knowledge of using Virtuoso design suites such as Virtuoso Layout and Schematic Suites is not needed, you should be familiar with how to perform some basic tasks such as create a new library and cell views. Although you can use any editor to write your SKILL programs, I recommend you become familiar with SKILL Integrated Development Environment (IDE) to enhance the productivity and efficiency of your software development cycle.

Who would benefit from this book? I have written this book with two target audiences, academia and industry, in mind. Academia: any senior undergraduate/graduate student pursuing a career in integrated photonics. Industry: PIC circuit and mask designers, PIC component developers, Process Design Kit (PDK) developers, and PIC Computer-Aided Design (CAD) engineers.