Yu Liu

Yu Liu

I build instruments — and lately, a microscope you can afford.

Most of my work lives in the gap between a physics idea and a box that actually measures something — nanoparticles levitated in an ion trap, a spectrometer with no grating in it, a laser lock running on an FPGA. I usually end up owning the whole stack: the optics, the PCB, the firmware, and the reconstruction code on top.

I did my master's in quantum engineering at ETH Zürich, and engineering physics before that in Hong Kong. I like hardware that ships, and I'm suspicious of instruments that only work in the lab they were born in.

Now — building Eureka, a microscope with real optical quality at a price people will actually pay. Zürich. Always up for a conversation about optics, weird sensors, or starting things.

Work

Earlier work isn't all here — ask me for a CV
Master’s thesis

Engineering ultrastrong coupling between a membrane and a transmon

Hybrid Quantum Systems Group, ETH Zürich · Prof. Yiwen Chu, Dr. Simon Storz · 2026

Can a kHz Si₃N₄ membrane be coupled to a superconducting qubit hard enough to reach deep strong coupling? Theory, an FEM model with Bayesian-optimised tether geometry, and interferometry on real metallised membranes. For a transmon, no — pull-in arrives first. For a Cooper-pair box, yes.

Circuit QEDFEMInterferometry Thesis PDF →

A spectrometer with no grating

ETH Zürich · Optical Nanomaterial Group · 2024

Built the optical bench and data pipeline, then taught a convolutional autoencoder to invert it — as accurate as linear reconstruction.

PyTorch1 nm · 550–700 nmInverse problemsReport →

Ballistic gravimeter on a Paul trap

Team lead · ETH Photonics Lab · 2023 – 24

Drop a trapped nanoparticle, time the fall, get g. Designed the trap through ten revisions and debugged the high-voltage switching board.

g to 0.2 m/s²10⁻³ PaPCBReport →

FPGA frequency-to-voltage converter

ETH Quantum Optics Lab · 2023

A laser lock that beats FFT: 100 kHz resolution in a 10 µs window. Verilog through to Python — now running in several labs.

SystemVerilogRed PitayaQCE23 →

Why glass releases heat the way it does

Hong Kong PolyU · Prof. Chi-hang Lam · 2021 – 22

Thousands of lattice-model runs in C++ to pull a power law out of the data, and a two-level-system account that explains it.

C++SimulationStatistical physics

Keeping a quantum cascade laser cold

Lasense Technology · Hong Kong · 2021

A PID thermal package prototype, from design to bench test, plus the Ansys Icepak simulations behind a new gas-sensor product.

PIDAnsys IcepakThermal

The Lab

Small things, built fast, for the fun of it
Tool live

Life-finance simulator 人生财务推演台

Cash flow, compounding and risk, settled month by month, with every assumption on a slider. Runs entirely in your browser — nothing you type leaves it.

cashflow.yuliu.dev →
Exhibition live

Wisdom in Pieces

Forty rules about risk and asymmetric bets, each paired with a low-poly sculpture, plus decision trials to test whether any of it stuck.

wisdom.yuliu.dev →
Generative

Fri(i)ends

AI-assisted portraits of my friends, minted as a small NFT collection. Mostly an excuse to take a Stable Diffusion pipeline apart.

On Rarible →

Writing

Notes on optics, hardware, and getting things to work
Nothing published yet — the first one is in progress

Off the clock

Music

I wrote and produced an album about the life that starts after you leave home.

Making pictures

AI-assisted art, usually made as a gift rather than a portfolio piece.

Making things

3D printing, small mechanisms, and whatever needs to exist by Friday.

Education

  • M.Sc. Quantum Engineering — ETH Zürich2022 – 26
  • B.Sc. (Hons) Engineering Physics — Hong Kong PolyU2018 – 22

Publication

Laser Frequency Stabilization Using a Prescaler and a High-Resolution Frequency to Voltage Converter Y. Liu, A. Frank, T. Esslinger, T. Donner, A. Akin IEEE QCE, 2023 · Xplore

Awards

  • ETH Quantum Hackathon — honorable mention, NVIDIA track2024
  • Innosuisse Business Concept — first runner-up2023
  • First Class Honours & Dean's Honour List, PolyU2022
  • Plancks Physics Competition — HK representative2021
  • Hong Kong Jockey Club Scholarship2020

Say hello

Easiest at hey@yuliu.dev. I answer most things, and I'm especially happy to talk about optics on a budget, instruments that escape the lab, or building a hardware team from nothing.