The far-field pattern and its intensity profile during laser oscillation (Fig. 3 (c), (d)) show that the oscillation was achieved with an extremely narrow beam divergence angle (of as low as 0.05°), ...

Niels Gregersen and co-workers show that by tapering the nanowires, the divergence of the output beam can be reduced. The proposed nanowire structure consists of a GaAs tip with a tip angle as ...