Justin Lee

Projects

Research in optoelectronics. Experiments in engineering.

Current research · Stony Brook University

III–V–Sb avalanche photodiodes

Semiconductor heterostructures for infrared detection.

Aug 2026–present
Optoelectronics laboratory with an optical table, cryostats, measurement instruments, and a workstation.
Inside the optoelectronics labFrom the lab

Research Assistant, Optoelectronics Group · August 2026–present

Research focus

I study III–V–Sb separate absorption and multiplication avalanche photodiodes for infrared detection. The work examines how semiconductor heterostructure design shapes photodetector behavior.

What I’m studying

  • InAsSb absorber layers and AlGaAsSb multiplication layers.
  • Carrier transport through the heterostructure.
  • Impact ionization, avalanche gain, and their relationship to device performance.

My role

I support the group’s ongoing research through analytical, experimental, and technical work under faculty supervision.

Semiconductor devicesInfrared detectionOptoelectronics

Photos and videos from the lab.

Close-up of the APD mounted in a gold butterfly package.
APD on a butterfly chipThe APD device and its package.
Spectrum analyzer screen displaying a measurement trace.
Spectrum analyzerA measurement display from the lab.
Cooling the cryostat0:03Liquid nitrogen being poured into the cryostat.
Connecting a wire0:03A close-up of a wire being connected.
Research internship · Brookhaven National Laboratory

Quantum optics: motorized laser alignment

Optical alignment through motorized positioning and Bayesian optimization.

Jun–Aug 2025
The quantum optics setup with motorized optical mounts, control electronics, fiber, and a photodiode amplifier.
The complete quantum optics setupFrom the lab

Quantum optics & instrumentation · June–August 2025

The system

I built a motor-based free-space optical setup for laser coupling and alignment. The system brings together optical components, mechanical adjustment, and electronic controls to align light into a single-mode optical fiber.

Optimization & experimentation

I applied Bayesian black-box optimization to search for useful coupling configurations, alongside hands-on optical alignment and instrumentation troubleshooting.

Related preprint

The work is described in Black-Box Optimization Method in a Motorized Optomechatronic System for Light Detection and Alignment, an Optica Open preprint from 2025.

Read the preprint

Free-space opticsBayesian optimizationInstrumentation

Photos and videos from the lab.

Motor drivers and green control boards connected by colored wiring on the lab bench.
The circuit behind the motionMotor drivers, control boards, and wiring.
Motorized optical mounts and fiber components on a black optical breadboard.
Optical mounts on the breadboardThe optical components and positioning hardware.
Motors in action0:25A close-up of the motorized positioning hardware in motion.
Photodiode amplifier readings0:21The photodiode amplifier display as its readings change.
Independent hardware project

Optical transceiver

A design for 10 Gbps optical communication, from circuitry to signal recovery.

Apr–Aug 2026
PCB layout for Justin Lee's optical transceiver project.
Optical transceiver · PCB layoutView full size ↗

Analog circuits & signal processing · April–August 2026

Design objective

A 10 Gbps optical transceiver design to explore high-speed optical data modulation, transmission, and signal recovery.

Circuitry & layout

  • Laser-driver circuitry for optical modulation.
  • Transimpedance amplifiers for signal recovery.
  • Impedance matching and differential-pair routing.
  • High-frequency signal integrity and crosstalk control.

Characterization

I evaluated electro-optical performance using eye diagrams, bit error rate (BER), and signal-to-noise ratio (SNR) measurements with high-bandwidth test equipment.

Analog circuitsSignal integrityPCB design

Miscellaneous projects

a variety of other projects completed over the years

Jan 2023–Feb 2026
Electronics, tools, and a small wheeled build laid out in a workspace.
A wooden truss held above a table of construction materials.
A long wooden frame with triangular bracing on a worktable.
A wooden structure with a raised central frame and diagonal supports.
Wood strips stored upright for project construction.
A tapered wooden tower with cross bracing.
A motorized vehicle with blue wheels, batteries, and electronic controls.