Picosecond Explained

picosecond
Symbol:	ps
Standard:	SI
Quantity:	time
Units1:	SI units

A picosecond (abbreviated as ps) is a unit of time in the International System of Units (SI) equal to 10⁻¹² or (one trillionth) of a second. That is one trillionth, or one millionth of one millionth of a second, or 0.000 000 000 001 seconds. A picosecond is to one second as one second is to approximately 31,689 years. Multiple technical approaches achieve imaging within single-digit picoseconds: for example, the streak camera or intensified CCD (ICCD) cameras are able to picture the motion of light.^{[1] [2]}

One picosecond is equal to 1000 femtoseconds, or 1/1000 nanoseconds. Because the next SI unit is 1000 times larger, measurements of 10⁻¹¹ and 10⁻¹⁰ second are typically expressed as tens or hundreds of picoseconds. Some notable measurements in this range include:

• 1.0 picoseconds (1.0 ps) – cycle time for electromagnetic frequency 1 terahertz (THz) (1 x 10¹² hertz), an inverse unit. This corresponds to a wavelength of 0.3 mm, as can be calculated by multiplying 1 ps by the speed of light (approximately 3 x 10⁸ m/s) to determine the distance traveled. 1 THz is in the far infrared.
• 1 picosecond – time taken by light in vacuum to travel approximately 0.30 mm
• 1 picosecond – half-life of a bottom quark
• ~1 picosecond – lifetime of a single (hydronium) ion in water at 20 °C^[3]
• picoseconds to nanoseconds – phenomena observable by dielectric spectroscopy
• 1.2 picoseconds – switching time of the world's fastest transistor (845 GHz, as of 2006)^[4]
• 1.7 picoseconds – rotational correlation time of water^[5]
• 3.3 picoseconds (approximately) – time taken for light to travel 1 millimeter
• 10 picoseconds after the Big Bang – electromagnetism separates from the other fundamental forces
• 34 picoseconds – signal rise time (20% to 80%) of a SFP+ transmitter for 10 Gigabit Ethernet.^[6]
• 10–150 picoseconds – rotational correlation times of a molecule (184 g/mol) from hot to frozen water^[7]
• 100 picoseconds – Unit Interval of a 10 Gbps serial communication link, such as USB 3.1.^[8]
• 108.7827757 picoseconds – transition time between the two hyperfine levels of the ground state of the caesium-133 atom at absolute zero
• 330 picoseconds (approximately) – the time it takes a common 3.0 GHz computer CPU to complete a processing cycle

See also

• SI unit
• Second
• Nanosecond
• Microsecond
• Millisecond
• Jiffy (time)
• Orders of magnitude (time)

External links

• National Institute for Standards and Technology Glossary

Notes and References

1. Web site: Trillion-frame-per-second video. Massachusetts Institute of Technology. 2014-03-06.
2. Web site: Ultra high speed CCD cameras capture the motion of light.. Stanford Computer Optics. 2014-03-06.
3. Web site: Lifetime of single hydronium (H3O+) ion at 20°C . BioNumbers . 2011-10-10 .
4. Web site: World's Fastest Transistor Approaches Goal of Terahertz Device. James E. Kloeppel. 2006-12-11.
5. Lankhorst. D.. Schriever, J. . Leyte, J. C. . Determination of the Rotational Correlation Time of Water by Proton NMR Relaxation in H217O and Some Related Results. Berichte der Bunsengesellschaft für physikalische Chemie. 1982. 86. 3. 215–221. 10.1002/bbpc.19820860308.
6. Web site: SFF-8431 Specifications for Enhanced Small Form Factor Pluggable Module SFP+. SFF Committee.
7. Bulla . I. . Törmälä . P. . Lindberg . J. J. . Mikalsen . Ø. . Southern . J. T. . Edlund . K. . Eliasen . M. . Herskind . C. . Laursen . T. . Pedersen . P. M. L. . Spin Probe Studies on the Dynamic Structure of Dimethyl Sulfoxide-Water Mixtures . Acta Chemica Scandinavica . 29a . 89–92 . 1975 . 10.3891/acta.chem.scand.29a-0089. free .
8. Web site: Universal Serial Bus 3.1 Specification.