The invention resides in the innovative use of deposition techniques in deformable mirrors. The use of deposition techniques allows contact pads for electrodes to be located wherever convenient. When applied to bimorph mirrors the invention enables both electro-restrictive layers to become active, increasing the stroke of the deformable mirror whilst retaining temperature insensitivity. A controllably-deformable mirror according to the invention comprises a deposition layer; a first electro-restrictive plate; a mirror surface; and a plurality of electrodes comprising a set of electrodes defined as regions on a first surface of the first electro-restrictive plate, the set of electrodes comprising a first electrode and a second electrode; and a common electrode on a second surface of the first electro-restrictive plate.
