System and method for particle characterization

A particle detection and characterization system comprising:

• a current confining pixel (CCP) comprising:
• a first photodiode having a first polarity and defining a first detection surface,
• a second photodiode electrically connected to the first photodiode at a first conductive pathway and a second conductive pathway, the second photodiode having a second polarity opposing the first polarity and defining a second detection surface,
• a sense node electrically coupled to the first conductive pathway, and
• a reference node electrically coupled to the second conductive pathway;
• a first light source defining a first illumination region that intersects the first surface, arranged along a direction normal to the first surface, the first light source operable between an on state and an off state;
• a second light source defining a second illumination region that intersects the second surface, wherein the first surface is arranged opposite the second surface along the direction, the second light source operable between the on state and the off state;
• and
• a modulator that operates the first and second light sources between a first mode and a second mode, wherein in the first mode the first light source is in the on state and the second light source is in the off state and in the second mode the first light source is in the off state and the second light source is in the on state.

A method of particle detection and characterization, comprising:

• detecting, at a current confining pixel (CCP) comprising a pair of detectors arranged in an inverse polarity configuration, an optical signal having an intensity, wherein the intensity is based on a particle parameter;
• generating, at the CCP in an analog optoelectronic domain, a bipolar differential signal based on the intensity of the optical signal at each of the pair of detectors of the CCP;
• extracting, at a processor communicatively coupled to the CCP, the particle parameter from the differential signal;
• producing an output based on the particle parameter.