Acronym · Photonics, MEMS & Sensors
PIC (Photonic Integrated Circuit)
A chip that routes and manipulates light on-die, integrating waveguides, splitters, modulators, filters and detectors in place of discrete bulk optics. Platforms include silicon, silicon nitride, indium phosphide and thin-film lithium niobate.
- Also known as
- Photonic IC, Optical IC
- Type
- Acronym
- Domain
- Photonics, MEMS & Sensors, Silicon photonics
Notes
Photonic PDKs are far less mature than electronic ones, so PIC design still leans heavily on custom simulation and foundry-specific building blocks.
Overview
A PIC (photonic integrated circuit) is a chip that generates, guides, modulates and detects light using two or more optical components integrated on one substrate, in the way an electronic integrated circuit combines transistors and wires. PICs replace assemblies of separate lenses, fibres and optical parts with patterned structures made by wafer processing. They are used mainly in optical communications, and increasingly in sensing, computing and quantum technology.
How it works
A PIC is built from a small set of building blocks. Waveguides carry light around the chip; splitters and couplers divide and combine it; phase shifters and modulators change its phase or intensity to encode data; filters and multiplexers separate wavelengths; lasers or amplifiers provide light; and photodetectors turn it back into an electrical signal. Most PICs work at near-infrared wavelengths, typically between about 850 and 1650 nanometres.
The choice of material platform sets what can be integrated. Indium phosphide can integrate lasers, amplifiers, modulators and detectors on one chip and is one of the most widely used commercial platforms. Silicon, as in silicon photonics, offers large wafers, mature fabs and close integration with electronics, but needs light sources bonded or attached from other materials. Silicon nitride provides very low-loss passive circuits, and thin-film lithium niobate is used for fast, efficient modulators. Products often combine platforms.
Design follows a flow similar to electronics: device and circuit simulation, layout using a foundry's design kit, design rule checks, then fabrication, wafer test and packaging. Packaging is demanding, because fibres and light sources must be aligned precisely to the chip's waveguides. Multi-project wafer services, which share a fabrication run among many designs, have lowered the cost of prototyping.
Examples
- Silicon photonics transceivers for data centres, which Intel began shipping at 100G in 2016.
- An indium phosphide PIC that integrates lasers, modulators and detectors on one chip for optical communications.
- A multi-project wafer prototype built through AIM Photonics' 300 mm foundry service using its process design kit.
- GlobalFoundries silicon photonics processes with micro-ring modulators and integrated photodiodes for pluggable and co-packaged optics.
- Photonic chips for LiDAR sensing or lab-on-a-chip biomedical tests.
Why it matters
Related terms
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Where it appears on the Hub
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Lifecycle stages and gates
Roles
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Last reviewed . Written by The Semiconductor Hub editorial team. The full glossary