Skip to content
QubitWire
A compact circuit assembly rests on a yellow surface with multiple cables attached along one edge.
Daderot — Optical switch - DARPA Quantum Network, in the BBN laboratory - IMG 2681.jpg — CC0 — https://commons.wikimedia.org/wiki/File:Optical_switch_-_DARPA_Quantum_Network,_in_the_BBN_laboratory_-_IMG_2681.jpg — http://creativecommons.org/publicdomain/zero/1.0/deed.en.
Components · Photonic

An optical switch in a quantum-network experiment

A network diagram makes switching look like a simple symbol. This archive photograph turns that symbol into a physical object with connectors, wiring and a mounting surface. The source identifies it as an optical switch used in the DARPA Quantum Network, not as a complete quantum network. That limited claim is enough to support a useful explanation of the equipment hidden behind a connection map. Ask which information belongs to the image, which comes from its caption and which would require a circuit or network document. Preserve the historical date when comparing the component with modern integration goals.

Organization
DARPA Quantum Network / BBN
Image type
Photograph
Capture date
2003-11-06
Photographer / creator
Daderot
Reuse terms
CC0

Daderot — Optical switch - DARPA Quantum Network, in the BBN laboratory - IMG 2681.jpg — CC0 — https://commons.wikimedia.org/wiki/File:Optical_switch_-_DARPA_Quantum_Network,_in_the_BBN_laboratory_-_IMG_2681.jpg — http://creativecommons.org/publicdomain/zero/1.0/deed.en.

Full original frame retained; EXIF orientation normalized where present, resized without enlargement and converted to WebP. No crop or content alteration.

View original source ↗Explore components
Open full-screen viewer

Read the image

A network switch makes routing a physical operation

A compact circuit assembly rests on a yellow surface with cables attached along one edge. The source identifies an optical switch in the DARPA Quantum Network at BBN, photographed in November 2003. Its appearance is modest compared with a large laboratory table, but its role belongs to the organization of a network path.

Routing concerns where a signal is directed. In a quantum communication experiment, the path must be compatible with the properties the protocol depends on. A switch’s control interface, transmission and effect on the signal therefore matter alongside the abstract network connection it represents.

The image does not identify all internal optical functions from the visible circuitry. Use it to connect a network diagram’s routing node with a real component, while keeping device-specific specifications in the technical source. It is also a reminder that classical electronics can control equipment serving a quantum communication task.

Is a routing switch automatically a quantum logic gate?

No. Directing a signal between paths and implementing a specified quantum logic operation are different functions, even when optics is involved in both.

What would a useful component record include?

Identify the routes, control interface, signal compatibility, loss and switching behavior under stated conditions.

Why retain the 2003 date?

The photograph documents early network research. It should not imply that the same hardware is a current product or deployment.

An independent QubitWire lesson based on this image and the cited source reading. The image does not establish a performance result.

Keep exploring

More from the same organization or hardware architecture.

Optical mounts and connected equipment cover a laboratory table beneath a row of electronic instruments and a monitor.The optical bench of an early quantum-network linkSame organization · DARPA Quantum Network / BBNDaderot · CC0A silver electronic instrument has front-panel connectors, controls and a display, with a sheet of paper resting on top.An early single-photon detector instrumentSame organization · DARPA Quantum Network / BBNDaderot · CC0A black optical instrument on a tripod stands beside a window facing a brick building across an open space.A free-space endpoint facing another buildingSame organization · DARPA Quantum Network / BBNDaderot · CC0An open rack is filled with instruments, cables and a cylindrical component beside additional laboratory equipment.The instrument stack around a photon detectorSame organization · DARPA Quantum Network / BBNDaderot · CC0A circular semiconductor wafer reflects rainbow colors across a grid of rectangular photonic-device patterns.A 300 mm quantum photonic waferSame architecture · PhotonicAFRL Information Directorate · NQI gallery reuse permissionRows of tiny patterned photonic-device cells reflect green, gold and violet light across a wafer.Patterns on a photonic waferSame architecture · PhotonicAFRL Information Directorate · NQI gallery reuse permission

Back to all images · Explore the interactive Model · Image rights and corrections