Deformable mirrors (DM) are mirrors whose surface can be deformed, in order to achieve wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics. They are also finding a new use in femtosecond pulse shaping.The shape of a DM can be controlled with a speed that is appropriate for compensation of dynamic aberrations present in the optical system.