The invention relates to a magneto-optical light modulator (100) for modulating light based on a physical property provided as an input to the modulator (100), the modulator (100) comprising a substrate (114) with a region of material (130) comprising a film of Eu(1-x)Sr(x)MO3 (112), an optical waveguide (106; 108) adapted for directing light through the region of material (130) and a first control unit, the first control unit being adapted to—maintain the region of material (130) at a constant predefined temperature in case the physical property is an input magnetic field subject to the region of material (130) or—maintain the region of material (130) subjected to a constant predefined magnetic field in case the physical property is an input temperature of the region of material (130), the light modulator (100) being adapted to perform the modulation of the light using the birefringence of the region of material (130), the birefringence depending on the physical property.