An optoacoustic imaging system includes an ultrasound transducer array, first and second light sources and a switching power supply that generates power for the light sources. The switching power supply includes an input for impeding its switching operation. A data acquisition unit samples the ultrasound transducer array for a first predetermined period of time after a pulse of light from the first light source and for a second predetermined period of time after a pulse of light from the second light source and stores the sampled data. A master processor utilizes the input to impede operation of the switching operation of the switching power supply during the first predetermined period of time after a pulse of light from the first light source, and during the second predetermined period of time after a pulse of light from the second light source.
