Fig. 1. (a) Schematic description of the experimental setup. (b) The SEM image of the metal grating sample; the period of the grating is about 450 nm. (c) Luminescence spectrum of QDs.

Fig. 2. (Color online) (a) The back focal plane image of the luminescence in grating sample A. (b) Phase relation for wave vectors of emissions and SPPs. k0 represent the actual direction of the emission light, and p is the grating period. (c) Schematic image of the Fourier plane. The black circle represents the actual view field, which we can observe from the back focal plane.

Fig. 3. (a)–(e) The SEM images of five samples, in which the Au gratings are etched through. The grating constants are (a) 450, (b) 500, (c) 650, (d) 850, and (e) 1050 nm, respectively. (f)–(j) The back focal plane images of the luminescence for the corresponding grating samples. (k)–(o) The back focal plane images of the luminescence for the corresponding grating samples, which have the same grating constant but are not etched through.

Fig. 4. (Color online) (a) The lifetime of QDs on bare silica substrate, where t=11.66ns. (b) The lifetime of QDs on the Au grating, where t=3.28ns.

Table 1. Directional Emission Angles for the Five Samples