Creation of a 50,000λ long needle-like field with 0.36λ width: reply

This is the reply to the comment by Chavez-Cerda and Pu [J. Opt. Soc. Am. A32, 1209 (2015)JOAOD61084-752910.1364/JOSAA.32.001209] on our recent work about the 50,000λ long needle-like field [J. Opt. Soc. Am. A31, 500 (2014)JOAOD60740-323210.1364/JOSAA.31.000500]. First, they employed an incorrect boundary condition as the fundament of their argument. In fact, it is not the electric field but its tangential component that must be zero at the surface of the perfect metal. Our result is completely consistent with the correct boundary condition. Second, a constant phase factor in the incident radially polarized beam, exp(jπ/4), for instance, has no influence on the result. Accordingly, our initial condition is proper.