A team at the Laboratory for Attosecond Physics (LAP) in Garching (Germany) has constructed a detector, which provides a detailed picture of the waveforms of femtosecond laser pulses. Knowledge of the exact waveform of these pulses enables scientists to reproducibly generate light flashes that are a thousand times shorter – lasting only for attoseconds – and can be used to study ultrafast processes at the molecular and atomic levels.
Modern mode-locked lasers are capable of producing extremely short light flashes that last for only a few femtoseconds. In one femtosecond light, which rushes from the Earth to the Moon in just one second, advances only three ten-thousandths of a millimeter. Such short pulses consist of only one or two oscillations of the electromagnetic field, which are preceded and followed by waves of lower amplitude that are rapidly attenuated. To be utilized in an optimal manner to probe ultrashort processes that occur at the level of molecules and atoms it is important to know the precise form of the high-amplitude oscillations.