A picosecond is an SI unit of time equal to 10−12 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 31,700 years. Multiple technical approaches achive imaging within single digit picoseconds. For example the Streak camera or intensified CCD (ICCD) cameras are able to picture the motion of light. 
The name is formed by the SI prefixpico and the SI unitsecond. It is abbreviated as ps.
One picosecond is equal to 1000 femtoseconds, or 1/1000 nanosecond. 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 picosecond – time taken by light in a vacuum to travel approximately 0.30 mm
^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 Chemie86 (3): 215–221. doi:10.1002/bbpc.19820860308.Cite uses deprecated parameters (help)
^Bulla, I.; Törmälä, P.; Lindberg, J. J.; Mikalsen, Ø.; Southern, J. T.; Edlund, K.; Eliasen, M.; Herskind, C.; Laursen, T.; Pedersen, P. M. L. (1975). "Spin Probe Studies on the Dynamic Structure of Dimethyl Sulfoxide-Water Mixtures". Acta Chemica Scandinavica29a: 89. doi:10.3891/acta.chem.scand.29a-0089.edit