Ultrafast Mirrors are standard, general purpose mirrors. They have a 99% reflection rate. They are characterized by short pulse durations, broad wavelength ranges, and high peak powers. Such pulses do not behave like laser light at lower powers, and standard optics can cause serious problems if used in the ultrafast regime. Specially designed optics are needed when working with pulse durations of picoseconds. They are often used during the ultrafast pulse generation process as well as for more standard functions such as steering. The ultrafast pulse bandwidth becomes wider as the pulse duration is shortened due to energy-time uncertainty.