Deformable optical system and method for controlling the same as well as a lithographic system comprising the deformable optical system

摘要

The deformable optical system comprises at least one optical element (10), an actuator facility (20) and a control unit (30). Therein the at least one optical element (10) has a body (12) with a thermal expansion coefficient and the actuator facility (20) serves to exert a force distribution at a main surface (16) of the body (12). The control unit (30) is arranged for controlling the actuator facility (20) in order to control a shape of the body (12). The actuator facility comprises a body layer (22) formed on said main surface (16) of the body (12) and the body layer has a thermal expansion coefficient differing from the thermal expansion coefficient of the body. The actuator facility further comprises a thermal array (24) facing the body layer (22) and distanced from said body layer (22) by a gap (26). The thermal array has a plurality of thermal elements (250, T i ,T 1 ,...T 5 ) distributed at a surface of the thermal array facing the body layer that allow for a heat flow between the thermal array and the body layer. The heat flow has an amplitude controlled by the control unit (30) as a function of the position on the thermal array and as a function of time.