A method of combining output of a plurality of light sources includes arranging a plurality of light sources in the same plane and having their beams directed at a first mirror, rotating the first mirror in the plane so as to direct the beams towards the same direction, and pulsing the light sources in synchronization with the rotation of the first mirror. The light sources can include, for example, pulsed lasers or lamps. The method can further include directing the beams from the first mirror towards a second counter-rotating mirror, wherein rotation of the second counter-rotating mirror compensates for angular displacement of the beams due to rotation of the first mirror. The method can also include orienting the first mirror at about 45 degrees relative to an incident path of the beams. This method can be used, for example, to expose a substrate in a lithography system.