In optics, an ultrashort pulse of light is an electromagnetic pulse whose time duration is of the order of a picosecond (10^-12 second) or less. Such pulses have a broadband optical spectrum, and can be created by mode-locked oscillators. They are commonly referred to as ultrafast events. Amplification of ultrashort pulses almost always requires the technique of chirped pulse amplification, in order to avoid damage to the gain medium of the amplifier.