ljuspuls

Ljuspuls is a term used in optics to denote a short burst of light. In English the equivalent is light pulse or optical pulse. A ljuspuls may last from femtoseconds to nanoseconds, with shorter pulses corresponding to broader spectral content. The concept is central to ultrafast optics and is associated with specialized light sources and measurement techniques. In Nordic languages, ljuspuls directly translates to light pulse.

Generation of ljuspuls is commonly achieved with ultrafast laser systems. Mode-locked lasers produce ultrashort pulses by phase-coherently locking the longitudinal modes of a resonator, yielding pulse trains with durations down to tens of femtoseconds. Q-switched lasers generate higher-energy pulses with somewhat longer durations, typically in the picosecond to nanosecond range, by briefly storing energy in the gain medium and releasing it in a short burst. Other sources include picosecond and femtosecond laser diodes and pulsed light-emitting diodes.

Key properties of a ljuspuls include pulse duration, energy per pulse, peak power, and repetition rate. The time-bandwidth limit links shorter durations to broader spectral bandwidth, so many ultrafast pulses have wide spectra. Pulse characterization and control also involve the pulse shape and phase.

Measurement and characterization employ techniques such as autocorrelation and cross-correlation to determine duration, while more advanced methods like frequency-resolved optical gating (FROG) and SPIDER recover the full electric-field waveform.

Applications of ljuspuls span time-resolved spectroscopy, nonlinear optics, micromachining, and biomedical imaging. They are used to study fast dynamics in materials and chemistry, to drive nonlinear interactions, and to enable high-speed optical processes in research and industry. Related concepts include laser pulse, femtosecond, picosecond, and ultrafast optics.