Ryoichi Ishihara

Associate Professor, Group leader

Qutech, Dep. Quantum and Computer Engineering, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology

Ishihara-lab focuses on the integration technologies for unconventional electronic systems; quantum computers, quantum sensors, neuromorphic computers, and biodegradable sensors. Our work involves new materials, scalable fabrication of electronic and photonic devices, and 3D heterogeneous integration, aiming to realize unconventional electronic systems.

Designing coherent photonic crossbar arrays for integrated artificial intelligence (AI) and machine learning (ML) accelerator system

The dramatic recent progress in the field of artificial intelligence (AI) and machine learning (ML) is pushing persistently for unprecedented computational power which is already overwhelming for the conventional computing systems. Also, the pace of the increase in computing power requirements is growing significantly faster than the progress in conventional computing and the Moore’s law. Therefore, we need to implement novel computing techniques to meet the demands of advanced AI, ML-based systems, and applications.

In this scenario, computing approaches with hardware accelerators, implemented using photonic crossbar arrays and phase-change materials (PCM), 2D optomemristive neurons, can potentially accomplish low latency and high efficiency matrix operations for computationally heavy applications, such as in AI, ML and deep learning. So, an analog optical computing system based on photonic crossbar arrays with phase-change materials or 2D optomemristive neurons can be a potential candidate to achieve large compute powers (TOPS) at high energy-efficiency (TOPS/W) for AI, ML acceleration in data centers and supercomputers.

However, the design and implementation of such practical system-level architectures compatible is highly challenging. Issues such as scalability, on-chip integration techniques & and compatibility, device footprints, power consumption etc. has to be considered and addressed carefully in the design. Compatible integration techniques have to be identified to realize a functional hardware accelerator system.

Project goal/tasks:

1. Research and identify an efficient, scalable integration route for a photonic crossbar-based AI accelerator architecture.
2. Design and develop the optical-electrical testing setup for coherent photonic crossbar arrays
3. Test a proof of principle coherent photonic crossbar (2×2) array for multiply-and-accumulate (MAC) operation.

References:

[1]. Nat. Phot. 9, pp. 725–732 (2015)

[2]. arXiv:2210.10851 (2022)

[3]. Nat. 589, pp. 52–58 (2021)

[4]. IEEE Journal of Selected Topics in Quantum Electronics: Optical Computing 29, 2 (2023)

Interested? Please contact Ryoichi Ishihara r.ishihara@tudelft.nl or Salahuddin Nur <S.Nur@tudelft.nl>