Fig. 8.

Dependence of (a) $r_{\min }$ and (b) $r_{\max }$ corresponding to the 5% threshold on $L$ and $l_c$. Black dashed lines indicate $r_{\min }=22\mathrm{nm}$ and $r_{\max }=171\mathrm{nm}$ corresponding to $L=\infty$. Reproduced with permission from Ref. 21, courtesy of Opt. Lett.