US Patent 11877828 Systems and methods for performing frequency-domain photoacoustic imaging

Systems and methods are disclosed that facilitate the reduction of both radio frequency (RF) noise and photoacoustic artefacts in differential photoacoustic radar imaging through a multi-step electrical and optical domain calibration method. An example two-step calibration method involves reducing RF image noise via an initial calibration step that involves the control of the relative amplitudes and phases of electrical driving modulation waveforms, while a second calibration step involves the differential suppression of photoacoustic artefact signals via tuning, in the optical domain, of the relative intensity the optical beams that are delivered to the sample. Another example embodiment involves the use of the standard deviation of the unwrapped phase that is obtained, after performing frequency-domain cross-correlation and an inverse transform to the time domain, to improve the amplitude signal that is employed to generate a differential photoacoustic radar image.