Tyler W. Hughes

Tyler W. Hughes

I build physics simulation software and use it to design hardware.

PhD
Applied physics at Stanford: machine learning with light, and gradient-based design of photonic devices.
Built
Tidy3D at Flexcompute: simulation software used across the photonics industry, including gradient-based optimization using automatic differentiation. Later led the photonics team.
Now
AI agents that run simulations and design photonic chips.
Gradient-based design

Designing devices with gradients

These simulators compute gradients, so an optimizer can shape a device on its own. I wrote ceviche in my PhD and built the gradient engine in Tidy3D, which runs on GPUs.

autograd · JAX · PyTorch
AI agents × simulation

Agents that design photonic chips

LLM agents with electromagnetic simulators run their own design loops and reach state-of-the-art devices.

arXiv 2026 · senior author
Physics × learning

Physical systems that learn

Analog machine learning with light. I showed how to train optical chips with backpropagation done in the light itself, and that waves can act as a recurrent neural network.

Optica 2018 → Science 2023 · Sci. Adv. 2019
Product & leadership

Tidy3D, from prototype to product

An early Flexcompute employee, I built Tidy3D's Python API, data model, and product design, then led the photonics team.

Flexcompute · 2019–now

I simulate the physical world with computers and use those simulations to design and optimize useful things. My focus is differentiable simulation: writing physics solvers that compute not just what a given device does, but a map of how every design parameter affects it. You can use that map to optimize your hardware over millions of parameters, but also to analyze it, make it more robust, or improve your models of it.

I'm currently a Technical Fellow at Flexcompute Inc., building our multiphysics intelligence platform across AI infrastructure, platform architecture, and agentic simulation interfaces. I spend much of my time hands-on, putting AI agents in the loop with real physics solvers to see how far the two can go together. I'm drawn to the boundary where AI learns about and reasons over the physical world, both as a way to accelerate science and as a rich domain for fundamental AI research.

Before that, as Head of Photonics, I led the development of our electromagnetic simulation products. I was one of Flexcompute's first employees and spent years in the weeds building Tidy3D, our open-source framework for cloud-based, GPU-accelerated electromagnetic simulation: its data model, its Python client, and its look and feel. It grew from a moonshot prototype into an established product used widely across the industry. My deepest technical contribution was its automatic differentiation engine, which differentiates through a full 3D Maxwell's equations solve on a cloud GPU cluster and gets the whole gradient from one additional (adjoint) simulation. It works with autograd, JAX, and PyTorch.

Before Flexcompute, I completed my PhD in Applied Physics at Stanford, advised by Prof. Shanhui Fan. My PhD work established some deep connections between physics and computation: I showed that wave physics can perform computation like a recurrent neural network, proposed and experimentally demonstrated backpropagation implemented in light signals for training optical neural networks, developed mathematical methods for gradient-based design in photonics, and created several open source solvers and design packages for simulation.

I studied physics at the University of Michigan and now live in New York City. When I'm not building things I'm usually traveling, cooking, or running around Central Park.

Flexcompute 2019 – present
  1. Research Scientist2019
  2. Principal Scientist2024
  3. Head of Photonics2025
  4. Technical Fellow2026

One of the first employees. Built Tidy3D's Python API, data model, product design, and automatic differentiation engine, taking it from prototype to a product used across the industry. As Head of Photonics, led the development of our electromagnetic simulation products. Now leading company-wide work on AI infrastructure, platform architecture, and moonshot research, including how customers and their AI agents connect to our solvers.

Stanford University · PhD, Applied Physics 2014 – 2019

Photonic hardware for machine learning, electromagnetic inverse design, and laser-driven particle accelerators on a chip. Advisor: Shanhui Fan.

Rasa · Machine Learning Intern Summer 2018

Open-source conversational AI: natural language understanding.

GudTech Inc. · Junior Software Engineer 2014

Full-stack development of inventory management software.

National University of Singapore, Centre for Quantum Technologies 2013

Surface ion trapping for quantum information processing. Advisor: Manas Mukherjee.

University of Michigan, Optoelectronic Components and Materials 2010 – 2013

Wafer reuse for low-cost, thin-film III–V photovoltaic devices. Advisor: Stephen Forrest.

University of Michigan · BS Physics 2009 – 2013
AI agent designing photonic component
Research Flexcompute Engineering Blog
Can AI Agents Autonomously Design Components on Photonic Chips?

AI agents equipped with an electromagnetic simulator and design rule checker tackle photonic component design (waveguide bends, crossings, splitters, and demultiplexers) through iterative simulation and optimization. Explores where agentic AI excels and where it hits the limits of parametric search.

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Waveguide bend optimization evolving
Tutorial Flexcompute Engineering Blog
Designing a Photonic Chip Component with ~45 Lines of Python

A compact introduction to photonic inverse design using Tidy3D. Combining electromagnetic simulation with the adjoint method, a simple 10-iteration optimization loop discovers a waveguide bend achieving ~89% power transmission through a 90° corner.

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Latest
Photonic chip with agent-designed passive devices, microring modulators, Mach-Zehnder modulators, and RF electrodes
arXiv (2026)
Senior Author
Autonomous agentic design for photonics
We task large language models with solving photonic design problems, giving agents access to electromagnetic simulation tools and quantitative acceptance criteria (fabrication rules, geometric and physical-consistency checks). The agents run autonomous design loops (propose, simulate, evaluate, iterate) to produce devices with state-of-the-art performance across passive components (waveguide bends, splitters, crossings), an active silicon microring modulator, and the RF traveling-wave electrodes of a Mach-Zehnder modulator.
Prashanta Kharel, Amin Khavasi, Xinzhong Chen, and Tyler W. Hughes
First & Co-First Author
Wave physics RNN
Science Advances (2019)
Co-First Author
Wave Physics as an Analog Recurrent Neural Network
We show that wave-based physical systems map exactly to the mathematics of recurrent neural networks. Using this correspondence, wave systems can be trained to passively perform machine learning tasks on sequential data (raw audio, optical signals) using only wave propagation through a structure.
Tyler W. Hughes*, Ian A.D. Williamson*, Momchil Minkov, and Shanhui Fan
Training photonic neural networks
Optica (2018)
First Author
Training of Photonic Neural Networks through In-Situ Backpropagation and Gradient Measurement
We introduce a method for measuring adjoint sensitivity directly as an intensity measurement in a photonic device, allowing the backpropagation algorithm to be physically implemented using optical signals. This enables efficient in-situ training of artificial neural networks built from integrated photonic circuits.
Tyler W. Hughes, Momchil Minkov, Yu Shi, and Shanhui Fan
Forward-mode differentiation Maxwell
ACS Photonics (2019)
First Author
Forward-Mode Differentiation of Maxwell's Equations
Differentiating electromagnetic simulations is useful for photonic device design, optimization, and sensitivity analysis. We provide a method for computing exact derivatives of Maxwell's Equations based on forward-mode differentiation, complementing the adjoint (reverse-mode) approach.
Tyler W. Hughes, Ian A.D. Williamson, Momchil Minkov, and Shanhui Fan
Adjoint nonlinear nanophotonics
ACS Photonics (2018)
Co-First Author
Adjoint Method and Inverse Design for Nonlinear Nanophotonic Devices
We extend adjoint-based gradient computation to the frequency-domain analysis of nonlinear optical devices, enabling efficient large-scale inverse design with respect to many design degrees of freedom simultaneously. Demonstrated on photonic power switches.
Tyler W. Hughes*, Momchil Minkov*, Ian A.D. Williamson, and Shanhui Fan
Co-authored
Experimental Backprop
Science (2023)
Experimentally realized in situ backpropagation for deep learning in photonic neural networks
Experimental confirmation of the in-situ optical backpropagation method I introduced theoretically in 2018. Collaborators built an integrated optical circuit implementing a photonic neural network and measured gradients of a machine learning task using interference between optical signals.
Sunil Pai, Zhanghao Sun, Tyler W. Hughes, Taewon Park, Ben Bartlett, Ian AD Williamson, Momchil Minkov, Maziyar Milanizadeh, Nathnael Abebe, Francesco Morichetti, Andrea Melloni, Shanhui Fan, Olav Solgaard, David AB Miller
Anderson localization
Nature Physics (2023)
Anderson localization of electromagnetic waves in three dimensions
In this work, we used our electromagnetic simulator to observe direct evidence of Anderson localization in 3D optical systems for the first time, settling a long-standing debate in the physics community. This work required thousands of simulations of light scattering in extremely large ensembles of random spheres to gather statistics to back up these claims.
Alexey Yamilov, Sergey E Skipetrov, Tyler W. Hughes, Momchil Minkov, Zongfu Yu, Hui Cao
BONNI gradient-informed Bayesian optimization surrogate
Optics Express (2026)
Gradient-informed Bayesian and interior point optimization for efficient inverse design in nanophotonics
We introduce BONNI, which combines Bayesian optimization with neural-network ensemble surrogates and interior-point optimization, efficiently incorporating gradient information to improve global inverse design. The method outperforms standard optimizers on nanophotonic problems including distributed Bragg reflectors and dual-layer grating couplers.
Yannik Mahlau, Yannick Augenstein, Tyler W. Hughes, Marius Lindauer, and Bodo Rosenhahn
More First-Author
Metalens simulation
Applied Physics Letters (2021)
First Author
A perspective on the pathway toward full wave simulation of large area metalenses
We used Tidy3D to demonstrate full-wave simulation of a metalens with a diameter of hundreds of wavelengths. We argue that brute-force full-accuracy simulation provides a viable and increasingly practical pathway toward metalens design.
Tyler W. Hughes, Momchil Minkov, Victor Liu, Zongfu Yu, Shanhui Fan
Reconfigurable photonic circuit accelerator
Physical Review Applied (2019)
First Author
Reconfigurable Photonic Circuit for Controlled Power Delivery to Laser-Driven Accelerators on a Chip
We present a system for automatic control of laser power to an accelerator on a chip using a mesh of Mach-Zehnder interferometers that can be sequentially tuned to optimize power distribution.
Tyler W. Hughes, R. Joel England, and Shanhui Fan
On-chip laser power delivery
Physical Review Applied (2018)
First Author
On-Chip Laser Power Delivery System for Dielectric Laser Accelerators
We propose an integrated dielectric waveguide system for driving particle accelerators on a chip, providing a scalable path to larger energy gains and enabling practical applications of on-chip acceleration.
Tyler W. Hughes, Si Tan, Zhexin Zhao, Neil V. Sapra, YunJo Lee, Kenneth J. Leedle, Huiyang Deng, Yu Miao, Dylan S. Black, Olav Solgaard, James S. Harris, Minghao Qi, Jelena Vuckovic, R. Joel England, Robert L. Byer, and Shanhui Fan
Dielectric laser accelerator design
Optics Express (2017)
First Author
Method for Computationally Efficient Design of Dielectric Laser Accelerator Structures
We show how to systematically inverse design a dielectric accelerator structure using the adjoint method, showing an equivalence between maximizing particle energy gain and maximizing electron radiation.
Tyler W. Hughes, Georgios Veronis, Kent Wootton, R. Joel England, and Shanhui Fan
Plasmonic circuit theory
Nano Letters (2016)
First Author
Plasmonic Circuit Theory for Multiresonant Light Funneling to a Single Spatial Location
By modeling metallic nanostructures as electronic circuits, we systematically design them to focus light at the same position for multiple independently tunable frequencies, with applications in spectroscopy and biological sensing.
Tyler W. Hughes and Shanhui Fan
More co-authored
Parallel programming photonic network
IEEE JSTQE (2020)
Parallel programming of an arbitrary feedforward photonic network
We introduced a graph-topological approach that generalizes feedforward photonic networks, with an algorithm enabling efficient programming to implement arbitrary linear operations on demand.
Sunil Pai, Ian AD Williamson, Tyler W. Hughes, Momchil Minkov, Olav Solgaard, Shanhui Fan, David AB Miller
Inverse design photonic crystals
ACS Photonics (2020)
Inverse design of photonic crystals through automatic differentiation
We implemented guided-mode expansion using automatic differentiation and used gradient information to optimize photonic crystal dispersion and cavity quality factors.
Momchil Minkov, Ian AD Williamson, Lucio C Andreani, Dario Gerace, Beicheng Lou, Alex Y Song, Tyler W. Hughes, Shanhui Fan
Optical activation functions
Optics Express (2020)
Experimental realization of arbitrary activation functions for optical neural networks
Experimental demonstration of an on-chip electro-optic circuit realizing arbitrary nonlinear activation functions for optical neural networks.
Monireh Moayedi Pour Fard, Ian AD Williamson, Matthew Edwards, Ke Liu, Sunil Pai, Ben Bartlett, Momchil Minkov, Tyler W. Hughes, Shanhui Fan, Thien-An Nguyen
Electro-optic activation functions
IEEE JSTQE, Invited (2019)
Reprogrammable Electro-Optic Nonlinear Activation Functions for Optical Neural Networks
We propose a hybrid electro-optic circuit enabling nonlinear activation functions at low optical power, with an open-source ONN simulator demonstrating performance on standard ML tasks.
Ian A.D. Williamson, Tyler W. Hughes, Momchil Minkov, Ben Bartlett, Sunil Pai, and Shanhui Fan
Wafer recycling solar cells
Advanced Functional Materials (2014)
Non-Destructive Wafer Recycling for Low-Cost Thin-Film Flexible Optoelectronics
Demonstration of thin-film III-V device fabrication by lifting off the active region and reusing the substrate, dramatically reducing cost for high-performance photovoltaics.
Kyusang Lee, Jeramy D. Zimmerman, Tyler W. Hughes, and Stephen R. Forrest
Active nanophotonic adjoint
Optics Express (2018)
Adjoint-Based Optimization of Active Nanophotonic Devices
We show how the adjoint method may be used to inverse design periodically modulated optical devices. Our approach is based upon the multi-frequency finite-difference frequency-domain method. As a demonstration, we numerically design and optimize a compact optical isolator.
Jiahui Wang, Yu Shi, Tyler W. Hughes, Zhexin Zhao, and Shanhui Fan
Integrated accelerator chip
IPAC (2017)
Towards a Fully Integrated Accelerator on a Chip: Dielectric Laser Acceleration (DLA) From the Source to Relativistic Electrons
We discuss steps towards building a fully functional laser-driven particle accelerator on a chip, including a systematic overview of all necessary components and recent advances.
Kent Wootton, ..., Tyler W. Hughes, et al.
Flapping wing robot solar
IEEE TAP (2014)
Flexible Antenna Integrated With an Epitaxial Lift-Off Solar Cell Array for Flapping-Wing Robots
To demonstrate the applications of lightweight, thin film optoelectronic devices, we integrate a flying robot with thin-film, III-V photovoltaics, which are used for both power and wireless communication.
Jungsuek Oh, Kyusang Lee, Tyler W. Hughes, Stephen Forrest, and Kamal Sarabandi
Selected talks
Frontiers in Optics (2025) Visionary Speaker
Building the future of photonic design with machine learning
UW Madison Computing in Engineering Forum (2022) Invited
Hardware-accelerated FDTD for large-scale electrodynamics
CLEO (2019) Invited
Training of photonic neural networks through in situ backpropagation
Patents
2023 Efficient Analog Backpropagation Training Architecture for Photonic Neural Networks
2022 Simultaneous Measurements of Gradients in Optical Networks
2022 Training Wave-Based Physical Systems as Recurrent Neural Networks
2022 Systems and Methods for Activation Functions for Photonic Neural Networks
2021 Training of Photonic Neural Networks Through In Situ Backpropagation
Author
tidy3d 351 ★
GPU-accelerated 3D Maxwell's equations solver with a Python client, cloud execution, and full automatic differentiation support for gradient-based inverse design.
ceviche 419 ★
Differentiable frequency-domain electromagnetic simulation (FDFD). Computes exact gradients of Maxwell's equations with forward- and reverse-mode automatic differentiation, built on autograd.
angler 191 ★
Adjoint-based inverse design tool for nonlinear nanophotonic devices. Extends the adjoint method to frequency-domain nonlinear optics for gradient-based optimization of photonic structures.
Contributor
wavetorch 542 ★
Wave-based analog recurrent neural network simulator and trainer. Implements the wave physics / RNN correspondence, enabling physical systems to be trained on sequential data tasks.
neuroptica 271 ★
Simulation framework for optical neural networks built from integrated photonic circuits.

Things I build outside work.

A software twin of the Roland S-1 synthesizer: play it in the browser, and it learns any sound by gradient descent through a differentiable model of the synth. The code is on GitHub.
Learn jazz changes by playing them: it names every chord you hold, drills jazz progressions in all 12 keys, and walks you through a tune's changes until you know them by heart. Play a MIDI keyboard or your computer keys in the browser, through the S-1 twin if you like. The code is on GitHub.
Right-click any YouTube video and get the point in 30 seconds, then chat with its transcript. A Chrome extension and a tiny helper on your Mac that run on your own Claude plan: no API key, no server. Videos with no captions get transcribed locally with Whisper.
Film your pickleball game, tap MARK on the great points, and DinkReel cuts a highlight reel on your iPhone. No upload, no account, no waiting. It's on the App Store.
521
List 5, keep 2, pick 1: a tiny two-person decision ritual. Each turn travels as a link you text each other; there is no backend.