A scanning beam assembly comprising: a beam generator to generate a beam of radiation, and two or more oscillating reflectors configured to deflect the beam in sequence, each reflector being driven to contribute an incremental deflection of the beam so as to achieve a desired scanning beam waveform, at least one oscillating reflector aligned to receive the beam from the beam generator and deflect the beam to a second oscillating reflector, each oscillating reflector operating in a sinusoidal mode having a frequency and amplitude, and a controller for controlling the phase and/or frequency and/or amplitude of the oscillation of the reflectors so as to provide a desired scanning beam waveform.