Definition: chirped pulse

A pulse in which the wavelength changes during the duration of the pulse. In a diode laser, chirp arises from direct modulation of the laser, because the refractive index changes with the electron density. The output of a laser may be chirped intentionally to create a high-powered, extremely short pulse. In this case, the initial pulse from an oscillator is stretched out using optics, amplified and then compressed back to its original duration.