Generate
Laser-driven nonlinear structures or integrated emitters create single photons or entangled photon pairs.
FIELD GUIDE 01 — SILICON + LIGHT
Silicon photonics
meets quantum.
How chips that guide light could help quantum systems compute, communicate, and sense at scale.
SiPh / QPU
10⁻⁶ mchip-scale paths
cinformation carried by light
PHOTON GENERATION
◆WAVEGUIDES
◆INTERFERENCE
◆SINGLE-PHOTON DETECTION
01 / FOUNDATION
What is silicon photonics?
Silicon photonics is the design and manufacture of optical components on silicon chips. Instead of moving only electrical signals through metal wires, these circuits guide light through microscopic waveguides. Modulators control it, interferometers combine it, and detectors convert it back into electrical signals.
The technology grew around high-speed communications. Quantum engineers now use the same fabrication ideas to generate, manipulate, and measure quantum states of light on an integrated platform.
02 / THE SYSTEM
From photon to processor
A useful photonic quantum chip needs an entire chain—not one magic component.
Encode
Quantum information is encoded in path, time-bin, polarization, frequency, or continuous optical variables.
Interfere
Beam splitters, phase shifters, and interferometers transform optical modes and produce quantum operations.
Detect
Single-photon detectors measure outputs. Electronics interpret results and can feed corrections back into the circuit.
03 / WHY SILICON
Why build quantum optics on silicon?
Manufacturing maturity
Silicon can draw on decades of semiconductor process development, precise lithography, and repeatable wafer-scale production.
Dense integration
Long optical experiments assembled on a laboratory table can become compact networks of waveguides and interferometers.
Electronic control
Photonic circuits can sit near drivers, readout electronics, and conventional processors needed to operate a quantum system.
Network compatibility
Photons naturally carry quantum information across optical links, making them central to quantum communication and distributed computing.
04 / REALITY CHECK
Light travels well.
Computing with it is hard.
Photons interact weakly with their surroundings, which helps preserve quantum states. That same property makes deterministic two-qubit operations difficult. Many linear-optical operations are probabilistic and require extra photons, measurements, and active feed-forward.
Loss remains the defining engineering problem. A missing photon is missing information. Efficient sources, low-loss packaging, fast switching, high-performance detectors, and fault-tolerant architectures must work together.
How photonic quantum computers work →05 / APPLICATIONS
Where quantum photonics matters
Quantum processing
Interference and measurement implement algorithms using discrete photons or continuous optical fields.
Quantum networks
Photons distribute entanglement between remote processors and carry quantum states through fiber.
Quantum communication
Quantum key distribution uses measurable physical disturbance to reveal interception attempts.
Quantum sensing
Engineered states of light can improve measurements of time, displacement, fields, and biological samples.