A programmable multiple-point illuminator for an optical microscope (M) comprises a light source (1, 2)and a spatial light modulator (SLM) to modulate a light beam from the light source. The modulated light beam is intended to scan across a sample placed under the microscope objective (21), the sample being provided with fluorophores. The SLM comprises a first acousto-optic deflector (8) and a second acousto-optic deflector (9), the first acousto-optic deflector having a first modulation plane (81) and the second acousto- optic deflector having a second modulation plane (91), said two acousto-optic deflectors being arranged in cascade to provide respective deflection in different directions, whereby the SLM is enabled to scan in two dimensions across the sample. The SLM further comprises a telescope relay (10) to conjugate the first modulation plane with the second modulation plane. The illuminator also comprises an arbitrary waveform generator (13) that is configured to synthesize holograms, and is arranged to simultaneously inject a first such hologram into the first acousto-optic deflector and a second such hologram into the second acousto-optic deflector, in order for the SLM to modulate the light beam in response to said holograms.