Figure 2
Near-field energy density penetration inside the model nanograting (as shown in Fig. 1) calculated at different configurations of the incident beam. (a) Incidence angle is critical and azimuthal angle is less than critical – the field does not penetrate deep inside the sample structure. (b) Incidence and azimuthal angles are critical – the field penetrates the sample even if the incident angle is relatively small. (c) Incident angle is higher than critical (at the position of crossing of −1st- and 1st-order diffraction lines) and beam is parallel to the grating lines – the field penetrates the sample. (d) Incident beam angle is higher than critical and beam is far from parallel to the grating – the field looks uniform in the in-plane direction, so the structured layer can be treated as a thin-film layer of average density. |