Glossary

The "big brother" of the SFP module format, with four lanes that allow for speeds four times higher than the corresponding SFP.

A QSFP module designed for 100G data rate. QSFP28 integrates 4 transmit and 4 receiver channels. “28” means each lane carries up to 28G data rate. QSFP28 can do 4x25G breakout connection, 2x50G breakout, or 1x100G depending on the transceiver used.

QSFP Double Density: a QSFP device that doubles the number of channels and interfaces compared to a regular QSFP module. They have significantly more power consumption (15 Watts) and price.

A modulation process used in coherent systems that combines multiple levels of light intensity and phases of light to transmit more information in a light signal.

A device that uses the properties of quantum mechanics (superposition, interference, entanglement) to perform calculations. In theory, these computers can solve certain computational problems (such as the factorization behind encryption) much faster than classical computers.

A secure communication method that implements properties of quantum mechanics. These properties allow two communicating users to easily detect the presence of an eavesdropper.

Also called post-quantum or quantum-resistant encryption. Encryption algorithms that are thought to be secure against an attack by quantum computer.

The quantum version of a classical information bit. While a normal bit can be just 0 or 1, a qubit can have a combination of 0 or 1 states.