Shortpulses

Shortpulses are brief bursts of energy or information with durations that are small relative to surrounding timescales. In practice, they are most often discussed in optics and electronics, where pulses range from femtoseconds to nanoseconds. Shortpulses can be optical (light pulses), electrical (voltage or current pulses), or general waveform bursts produced by pulsed sources such as lasers or electronic oscillators. The term is used across disciplines to emphasize concise time structure rather than a fixed duration.

The defining characteristics of shortpulses include duration, peak power, energy per pulse, spectral bandwidth, and coherence. Because of the time–bandwidth trade-off, shorter pulses have broader spectral content. The repetition rate of pulses influences average power and the cumulative exposure in experiments. Pulse shape and phase can also be important for applications that rely on precise control of the electric field.

Generation methods commonly involve mode-locked lasers for ultrafast optical pulses, as well as gain switching or Q-switching in various laser systems for shorter optical bursts. Electrical shortpulses arise from fast pulse generators, step recovery circuits, or fast switching devices. Techniques such as pulse compression and chirped-pulse amplification are used to achieve extremely short durations or to manage dispersion, while nonlinear optical effects can shape or shorten pulses in appropriate media.

Applications of shortpulses span time-resolved spectroscopy and pump–probe experiments, ultrafast microscopy, precision material processing, high-speed communications, and the study of rapid dynamics in physics and chemistry. Measurement and characterization rely on autocorrelation, frequency-resolved optical gating (FROG), spectral phase interferometry for direct electric-field reconstruction (SPIDER), and related techniques. Challenges include maintaining pulse integrity through optics, dispersion management, synchronization of multiple channels, and preventing damage at high peak powers.