attojoule/second [aJ/s] Unit Converter

Definition of attojoule/second [aJ/s] unit

An attojoule per second is a derived SI unit of power equal to one quintillionth of a watt, or 10−18 watt. It describes an energy-transfer rate of one attojoule occurring every second and is abbreviated aW.

History of attojoule/second [aJ/s] unit

The unit combines the SI prefix atto-, meaning 10−18, with the joule-per-second definition of the watt. The prefix was adopted by the CGPM in 1964, joining the decimal prefix system for exceptionally small quantities. The joule honors physicist James Prescott Joule, while the watt honors engineer James Watt; both names became established SI-derived units through nineteenth-century metrology. Consequently, attojoule per second is not an independent base unit, but a scaled watt introduced for precision measurement. Its relevance expanded with nanotechnology, cryogenics, quantum devices, and ultra-sensitive electronic instrumentation.

Applications of attojoule/second [aJ/s] unit

Attojoule per second is used when power levels are extraordinarily tiny, especially in experimental physics and nanoscale engineering. Examples include characterizing energy dissipation in quantum sensors, estimating signals from single-photon or low-light detectors, describing minute leakage in microelectronic devices, and reporting heat or mechanical power in microscopic systems. It is commonly expressed as aW.

Complete list of attojoule/second [aJ/s] unit conversion