Mechanism of detector-selective coupling in continuous single-slit diffraction

Determine how a localized two-level sensor atom selectively interacts with a specific collective optical mode among the continuum of modes produced by a single-slit aperture, and ascertain how the spatial relationship between the detector and the photon state governs energy transfer within the Glauber light–matter interaction framework.

Background

Glauber’s first-order correlation accurately predicts diffraction intensity but does not detail which components of a multimode optical field couple to a localized detector. In continuous single-slit diffraction, many modes arise from different positions within the slit, complicating the identification of detector-coupled modes.

The authors explicitly note that the selective coupling mechanism and its dependence on detector position remain unclear at that point. They subsequently introduce a detector-oriented basis to address this, but the uncertainty is stated explicitly in the text prior to that development.