  In this manuscript, we present high spatial resolution focusing of
electromagnetic waves at telecommunication wavelengths ({\lambda}0 = 1.55
{\mu}m) by using high-refractive index mesoscale dielectrics placed at the end
of an optical fiber. Our approach exploits photonic nanojets (PNJs) to achieve
high-intensity, spatially narrow focal spots. The response of the device is
evaluated in detail considering 2-dimensional (2D) and 3-dimensional (3D)
configurations using high-index mesoscale cylindrical and spherical
dielectrics, respectively, placed on top of an optical fiber. It is shown how
the PNJs can be shifted towards the output surface of the mesoscale high-index
dielectric by simply truncating its 2D/3D cylindrical/spherical output profile.
With this setup, a PNJ with a high transversal resolution is obtained using the
2D/3D engineered mesoscale dielectric particles achieving a Full-Width at
Half-Maximum of FWHM = 0.28{\lambda}0 (2D truncated dielectric), and FWHMy =
0.17{\lambda}0 and FWHMx = 0.21{\lambda}0 (3D truncated dielectric). The
proposed structure may have potential in applications where near-field high
spatial resolution is required, such as in sensing and imaging systems.
