  Photonic hook is a high-intensity bent light focus with a proportional
curvature to the wavelength of the incident light. Based on this unique
light-bending phenomenon, a novel near-field photonic switch by means of a
right-trapezoid dielectric Janus particle-lens embedded in the core of a planar
waveguide is proposed for switching the photonic signals at two common optical
communication wavelengths 1310 nm and 1550 nm by using numerical simulations.
The signals at these two wavelengths can be guided to different routes
according to their oppositely bent photonic hooks to realise wavelength
selective switching. The switching mechanism is analysed by an in-house
developed three-dimensional (3D) Poynting vector visualisation technology. It
demonstrates that the 3D distribution and number of Poynting vector vortexes
produced by the particle highly affect the shapes and bending directions of the
photonic hooks causing the near-field switching, and multiple independent
high-magnitude areas matched by the regional Poynting vector streamlines can
form these photonic hooks. The corresponding mechanism can only be represented
by 3D Poynting vector distributions and is being reported for the first time.
