Common-path interferometric scattering imaging system and a method of using common-path interferometric scattering imaging to detect an object

A common-path interferometric scattering imaging system, comprising:

• an illuminating unit comprising a light source configured and arranged for emitting an illumination beam along an illumination optical path including at least two different phases of matter;
• a light collecting arrangement configured and arranged for simultaneously at least partially collecting through a common collection optical path:
• a scattered beam provided by the light scattering by an object of a portion of said illumination beam, wherein said object is placed in at least one of said two different phases of matter;
• and
• a reference beam provided by the reflection on or transmission through an interface of another portion of said illumination beam (L0), wherein said interface is a surface forming a common boundary among said two different phases of matter;
• an image sensor configured and arranged for receiving and sensing the collected scattered and reference beams interfering thereon as an interferometric light signal;
• a processor connected to said image sensor (D) to receive data corresponding to said interferometric light signal, and configured to process said received data to at least detect said object;
• and
• an attenuation mechanism arranged in said common collection optical path for attenuating said reference beam before it arrives at said image sensor, and in that said illumination optical path and said common collection path are configured and arranged such that the reference and scattered beams are generated at such closer positions that ensure a phase-locked relationship between the reference and scattered beams, the system being absent of any phase varying mechanism for said reference and scattered beams.