Role of spatial coherence in Goos–Hänchen and Imbert–Fedorov shifts: comment

Abstract

It is shown that the spatial Goos-Hänchen shift is greatly affected by spatial coherence. A typical example is given.

Observation of nonspecular effects for Gaussian Schell-model light beams

“…For what concerns the spatial GH shift, within our experimental errors, we observe the same effect for spatially coherent and partial spatially coherent beams. Our results resolve the recent theoretical controversy [16,17] on the spatial GH shift in favor of the theories exposed in refs [18,20]. For what concerns the angular GH and IF shifts we show that these last ones are affected by the presence of incoherence.…”

“…Although all the experimental work in this field has been performed till now with light beams that are spatially coherent, the role of incoherence in optical beam shifts has been the subject of recent theoretical debate [16,17]. Theories have addressed this topic by considering the specific case of Gaussian Schell-model (GS) beams that allows for an analytic treatment.…”

Goos-Hänchen Shifts of Partially Coherent Light Fields

“…From Fig. 1(c), for the cases of θ 0 being far away from θ c , the values ∆ m change much more for larger m. Thus it is expected that there must be a difference between the coherent and incoherent limits [10,15,16]. Comparing Fig.…”

“…Later, an experiment [11] showed the large difference between the measured GH shift of a partially coherent LED light and the theoretical result of a coherent light. However, the very recent investigations [12][13][14][15][16] have raised an important issue "whether the spatial coherence of the partially coherent fields (PCFs) influences the GH shifts?" Although the exact numerical results, calculated from our previous theory [10], are in good agreement with the experimental data [13,14,16], it is necessary to reconsider this issue thoroughly and bring to light the role of spatial coherence on the GH shift.…”

Spatial Coherence and Optical Beam Shifts

“…An exception is a recent experiment [18], which used a light-emitting diode (without spatial filter); the authors speculate that some non-understood aspects of their results could be due to the lack of spatial coherence of their source. The only theoretical papers, as far as we know, that address these issues are [19][20][21][22][23], where [19,21,23] lead to diametrically opposed results as compared to [20,22]. We aim in this paper to experimentally clarify the role of spatial coherence in beam shift experiments.…”