Definition of femtosecond in US English:


(also fs)


  • One quadrillionth of a second.

    • ‘Pulses of such short duration - lasting some 80 femtoseconds, or 80 quadrillionths of a second - shine a lightning-fast strobe light on the swift activities of atoms and molecules.’
    • ‘Femtosecond x-rays could shed new light on these coherent phonons by providing direct information about atomic displacements and enabling us to map out the energy transfer between vibrational modes and vibrational damping.’
    • ‘Since the extra energy being transferred from one molecule to the next changes the way each absorbs and emits light, the flow of energy can be followed through optical spectroscopy, resolved on a femtosecond timescale.’
    • ‘In other words, what could you do with a femtosecond x-ray source?’
    • ‘By the mid 1990s, scientists were building powerful lasers whose pulses were measured not in billionths or even trillionths of seconds but in thousandths of trillionths of seconds, or femtoseconds.’
    • ‘A femtosecond is to one second in duration what one second is to 30 million years.’
    • ‘With pulse widths measured in picoseconds and femtoseconds, these lasers apply cutting energy for such brief periods of time that they don't create troublesome heat-effect zones.’
    • ‘If you want to study this motion, you need femtosecond pulses of light.’
    • ‘Until recently, however, pulses on the order of a few femtoseconds were the shortest illumination sources available for the study of dynamic events.’
    • ‘At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds.’
    • ‘The other theory contends this conversion takes much longer, about 500 femtoseconds.’
    • ‘With pulse durations in the femtoseconds, scientists essentially could take the equivalent of a still photograph of extremely short-lived events, illuminating chemical interactions as they happened and creating a new understanding of how materials are formed from molecular constituents.’
    • ‘"It's the first time we've been able to watch the pathways the atoms follow in the first femtoseconds as the material transitions from solid to liquid," Lindenberg said.’
    • ‘Ultrafast lasers operate with pulses ranging from tens of femtoseconds to a few picoseconds.’
    • ‘Suslick counters that because chemical dissociations occur in mere femtoseconds, reactions would have been well underway even in the acetone bubbles.’
    • ‘In one second, there are more femtoseconds than there have been hours since the universe began roughly 14 billion years ago.’
    • ‘With femtosecond pulses, scientists could for the first time directly observe the shifts in interatomic spacings that take place during reactions.’
    • ‘The team created an electronic excitation by zapping the cluster with a femtosecond laser pulse.’
    • ‘The initial laser pulse measures 10 femtoseconds.’
    • ‘They sprayed oxygen and nitrogen molecules across the path of a laser tuned to emit pulses eight femtoseconds long and 15 microjoules in energy - just enough to split a single molecule.’