lightpulses

Lightpulses are brief bursts of electromagnetic radiation, typically in the optical range, that exhibit a well-defined temporal envelope and phase relationship. The duration of lightpulses ranges from femtoseconds to nanoseconds, with shorter pulses achieving higher peak powers and broader spectral content. Lightpulses are central to ultrafast optics and time-domain studies.

Generation methods rely on carefully engineered laser systems. Mode-locked lasers produce trains of pulses by establishing a fixed phase relationship among longitudinal modes. For shorter durations, techniques such as pulse compression and chirped-pulse amplification (CPA) are used; nanosecond-scale pulses are often produced by Q-switched lasers. Additional approaches include Kerr-lens mode locking and saturable-absorption methods to achieve stable, short pulses.

Properties of lightpulses are described by duration, energy per pulse, repetition rate, and spectral bandwidth. The shorter the pulse, the larger the spectral bandwidth required by the time-bandwidth product. Pulses can be shaped in time and spectrum using a variety of optical components and pulse-shaping devices, enabling precise control of amplitude and phase.

Measurement and characterization of lightpulses employ autocorrelation and interferometric techniques, such as Frequency-Resolved Optical Gating (FROG) and SPIDER, to recover duration and phase information. Pulse energy and peak power are assessed with calibrated detectors, while pulse shaping is often implemented with spatial light modulators and Fourier-domain optics.

Applications and impact of lightpulses are broad. They enable time-resolved spectroscopy, investigations of chemical dynamics and phase transitions, attosecond science, nonlinear optics, and precision laser micromachining. In communications and sensing, pulsed signals improve timing accuracy and signal integrity. Ongoing advances come from fiber lasers, semiconductor sources, and novel plasma-based generation methods.