A laser that pulses at one
quadrillionth of a second has been used in the UK for the first time.
A spokesman for University Hospital Southampton (UHS) said: "Known as the Femto LDV Z8, it pulses at one
quadrillionth of a second and is so precise it can cut the cornea into different planes which can be used to treat a number of different eye diseases."
That's a mindboggling speed, given that a femtosecond is a
quadrillionth of a second.
Due to its short pulses--lasting one
quadrillionth of a second--a femtosecond laser can vaporise material precisely, without heating the surrounding matter.
The new system is based on a femtosecond (one
quadrillionth of a second) streak camera and integrated a data acquisition type used in applications like tomography.
With our new system, you can selectively look in a desired direction and at a very small part of the picture in front of you at any given time, by controlling the timing with femto-second --
quadrillionth of a second -- precision," says Ali Hajimiri, Bren Professor of Electrical Engineering and Medical Engineering in the Division of Engineering and Applied Science at Caltech, and the principal investigator of a paper describing the new camera.
The new laser achieves 35 femtosecond pulses (a femtosecond is one
quadrillionth of a second) at a wavelength of 800 nanometers.
With the leap in laser technology from pulse duration measured in nanoseconds (1 billionth of a second) to one measured in femtoseconds (1
quadrillionth of a second) new vistas opened in the practice of cataract surgery.
(A femtosecond is one
quadrillionth of a second.) The breakthrough makes it possible to probe the ultra-fast motions that are involved in overcoming activation energy barriers to drive chemical reaction, including complex ones like protein folding.
In water, each bond lasts only one 100
quadrillionth of a second (Curtis, 1983), yet so many are being formed and broken at any given instant that they cause the water molecules in a drop of water to cling together with considerable strength and yet to resist clinging together further, even when pressure is applied to them.
(However, it is given as a main entry in our 1998 printing of Webster's New Collegiate Dictionary, 10th edition, where it is defined as one
quadrillionth of a second.)