“magnetic” Mie terms $b_i$. The expressions “electric” and “magnetic” refer to the fact that in the TE and TM case, the magnetic, respectively electric field components are zero in the scattering plane.

![Illustration of the experimental setup for (a) forward scattering and (b) backward scattering measurements. (c) sketch of the incident polarization configurations. The electric field is orientated either perpendicular (TE) or parallel (TM) to the NW axis. (d) SEM image of a cylindrical SiNW, deposited on a silicon substrate. The NWs for the spectroscopy experiments were deposited on a glass substrate, which could not be imaged in SEM due to charging. Scale bar is $100\,$nm. (e) SEM images of rectangular SiNWs. SEM images are obtained from a second sample on silicon on insulator (SOI) substrate. The spectroscopy sample is fabricated on transparent, but insulating SOQ substrate. Scale bars are $500\,$nm. Zoomed insets on the right are $200 \times 200\,$nm$^2$ (white dashed squares indicate zoom area). []{data-label="fig:fig2"}](fig2){width="\columnwidth"}

![image](fig3a) ![image](fig3b)

Let us now consider the case of sufficiently small nanowires, where only the first two orders of the Mie expansion contribute significantly to scattering. For SiNWs in the visible spectral range, this assumption is a good approximation for diameters up to 