The errata consist of corrections for one typo and one misinterpretation of the results regarding the antenna efficiency in the original article [Opt. Express 19, 12392–12401 (2011)].
© 2013 OSA
1. Correction 1
There is a typo in Eq. (1) in , where a factor of 2 is missing. The correct expression should read as1] since all results are normalized.
2. Correction 2
There is a mis-interpretation of the results regarding the antenna efficiency (Fig. 8) presented in the first paragraph on page 12400. The re-interpretation and derivations of the analytical expression of antenna efficiency are elucidated as the following.
The antenna efficiency, defined as ηeff = P rad(L)/P in × 100, is calculated based on the attenuation constant extracted (Fig. 6(b) in ). For nominal λ 0 = 1550 nm, the total and radiative attenuation constants are αt = −0.370k 0 and αr = −0.207k 0, respectively, which implies that the dissipative attenuation constant is αd = αt − αr = −0.163k 0. The power attenuation along the slot due to these loss mechanisms is illustrated in Fig. 1. (Note that Fig. 1 is used to replace Fig. 8 in  for better clarity.)
In order to calculate the radiated power P rad(L) for a slot of length L, the total attenuation in Fig. 1 is discretized into L = NΔz, where Δz is assumed infinitesimally small. Therefore, the radiated power can be written as the sum of the radiation from each Δz section as shown inEq. (2) is a geometric series, the antenna efficiency can then be written as Fig. 2, where the sum of these two loss mechanisms is shown to yield the expected total loss, hence confirming the validity of the approach in Eqs. (4) and (5).
In conclusion, the antenna efficiency can be extracted from the percentage of radiation in Fig. 2 (the blue dashed line). It is shown that it takes an antenna length of 0.5λ 0 to lose 90% of the input power; out of this total loss, 50.5% is due to radiation and 39.8% due to dissipation. Additionally, in order to lose 99% of the input power, the PLS antenna should be at least one wavelength long. Finally, a PLS with L = 1.5λ 0 attenuates 99.9% of the input power, which can be regarded as equivalent to an infinite slot.