Single-probe-beam differential amplitude and phase-scanning interferometer

We describe a common path differential amplitude and phase interferometer capable of measuring differential amplitude and phase responses simultaneously. The system uses a single probe beam that is imaged onto the detector plane; differentiation in any direction can be performed by the alteration of the position of the detectors. Experimental and theoretical results, which show excellent agreement, are presented to demonstrate how the transfer function of the system can be controlled to suit different application areas.