The influence of a tapering on nanowire light-emission profiles is studied. We show that, for nanowires with divergent output beams, the introduction of a conical tapering with a small opening angle reduces the beam divergence and increases transmission. This results in a dramatic increase in the collection efficiency of the detection optics. For a realistic tapering and a modest NA, the collection efficiency is enhanced by more than a factor of 2. This improvement is ensured by the adiabatic expansion of the guided mode in the tapering.
© 2008 Optical Society of America
Original Manuscript: March 11, 2008
Revised Manuscript: June 12, 2008
Manuscript Accepted: June 25, 2008
Published: July 24, 2008
Niels Gregersen, Torben R. Nielsen, Julien Claudon, Jean-Michel Gérard, and Jesper Mørk, "Controlling the emission profile of a nanowire with a conical taper," Opt. Lett. 33, 1693-1695 (2008)