Fig. 4.

(a), (b): Power emitted from devices W1 (panel a) and W2 (panel b) as a function of θ for input power of 15 mW. (c), (d): Fluorescence images of the emission of devices W1 (panel c) and W2 (panels d) for three different values of θ, the taper being submerged in a fluorescein droplet. White lines show the taper profile. (e), (f): Outcoupling angle of the light emitted from device W1 (panel e) and W2 (panel f) as a function of θ. (g), (h): Normalized radiance maps of the light emitted from devices W1 (panels g) and W2 (panels h) obtained through the ray tracing model for three different values of θ. Definitions of φ_x and φ_y are reported in Fig. 2(c). For each map the colorbar represents a 6 decades logarithmic scale.