Diffraction-Free Bloch Surface Waves.
Here, we demonstrate a diffraction-free Bloch surface wave sustained on all-dielectric multilayers that does not diffract after being passed through three obstacles or across a single mode fiber. It can propagate in a straight line for distances longer than 110 μm at a wavelength of 633 nm and could be applied as an in-plane optical virtual probe both in air and in an aqueous environment. Its ability to be used in water, its long diffraction-free distance, and its tolerance to multiple obstacles make this wave ideal for certain applications in areas such as the biological sciences, where many measurements are made on glass surfaces or for which an aqueous environment is required, and for high-speed interconnections between chips, where low loss is necessary.