Wiktionary
a. 1 Very short. 2 (context science English) Extremely short in duration, typically on the femtosecond scale 3 (context physics of a wave English) Having a wavelength of between 1 and 10 metres 4 (context finance English) Having a very short term of investment, typically less than a year n. (context finance English) A bond with an extremely short term, typically less than a year
Usage examples of "ultrashort".
A machine that generates an ultrashort wave, either of hertzian or sonic type, possibly of both.
He had developed the light—it was not light, but a combination of micro-length radio waves and sonic vibration in ultrashort wave lengths, as Doc had surmised—while experimenting in hopes of finding some method of bringing sight to certain types of blind.
Ever since the start of the attack direct communication with the Cyclops had been cut off and the men could only see whatever was sent via the probe's ultrashort wave rays across forty miles of vibrating atmosphere.
Pushing a small lever sufficed, as Khrest had explained some weeks ago, to change the structure of the energy screen, so as to render it permeable for ultrashort radio waves.