Quantum flow cytometer

A quantum flow cytometer for detecting an analyte with photon-number statistics, the quantum flow cytometer comprising:

• a flow cytometer that:
• receives a pump light in a first direction;
• receives an analyte flow comprising the analyte in a second direction;
• and
• produces scattered light from scattering the pump light by the analyte;
• a single photon detector in optical communication with the flow cytometer and that:
• receives, in a third direction, the scattered light from the flow cytometer;
• provides a correlative time-of-arrival waveform comprising photon-number statistics as an amplitude and an integrated area, the integrated area being proportional to a number of photons received by the single photon detector,
• wherein the first direction, the second direction, and the third direction are arranged at oblique angles;
• a sheath flow tube through which the sheath flow flows;
• an inner flow tube disposed in the sheath flow tube through which the analyte flow flows;
• a confluence tube in fluid communication with the sheath flow tube and the inner flow tube and in optical communication with the intensity interferometer such that the confluence tube:
• receives the sheath flow and the analyte flow;
• hydrodynamically focuses the analyte;
• constrains the flow of the analyte flow in a flow column within sheath flow in confluence tube;
• receives the pump light;
• and
• communicates the scattered light to the intensity interferometer.