I can't imagine what you mean by this. Every measurement or 'experience' of light relies on quanta of energy interacting with 'matter'. Diffraction calculations will give you the answer to the question of the energy distribution over any sensor.Bernadette said:And the light is in these experiences, considered as a particle.
I'm assuming this 'detector' is the eye or a camera so it would have sufficient resolution to identify the Fresnel Spot but it wouldn't necessarily be capable of measuring the actual angle subtended by the spot.tech99 said:Remember, however, that in order to resolve an image of the disc, the detector cannot be a point, but must have finite dimensions. The detector itself is then subject to interference effects, so the disc must be large enough to allow an effective directional detector to be employed.
I'd actually question the phrase "image of the disc". I would say that what you are seeing, when looking towards the light source, is actually a modified Image of the light source. This would be just the same as if you were looking through a lens or just through a hole. The 'position' of the spot, along the prime axis, would not be where the disc is - any more than any image is in the plane of a lens or even in the plane of your shaving mirror.
Imo, the nearest thing to this Fresnel Spot thing is what you see through a zone plate. In that case, the plate is much like a lens.