Background: The periodic dielectric multilayers sustaining Bloch surface waves have been proposed as a platform for the sensing applications and the two dimensional integrated optics. In this paper, we present the experimental and theoretical investigation of propagation properties of Bloch surface waves, for example propagation length and refractive index of the surface mode, at the interface of a dielectric multilayer platform. We use thin layers (~λ/25) of titanium dioxide as an additional layer of high index material. Methods: We exploit multi-heterodyne scanning near-field optical microscopy and total internal reflection configuration as a near-field and far-field characterization tools. Results: The longest propagation length is achieved when the multilayer is designed to have the dispersion curve positioned close to the middle of the photonics band gap. We measure a Bloch surface wave mode of propagation length 3.24 mm and of an effective refractive index contrast 0.15. Conclusions: The experimental results are in conformity with theoretical results. This study paves a way to realize efficient and compact two dimensional components and systems.

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We present, to the best of our knowledge, the first experimental investigation of a two-dimensional disk resonator on a dielectric multilayer platform sustaining Bloch surface waves. The disk resonator has been patterned into a few tens of nanometer thin (∼λ/25) titanium dioxide layer deposited on the top of the platform. We characterize the disk resonator by multi-heterodyne scanning near-field optical microscopy. The low loss characteristics of Bloch surface waves allowed us to reach a measured quality factor of 2×10³ for a disk radius of 100 μm.

Micro-sized spheres can focus light into subwavelength spatial domains: a phenomena called photonic nanojet. Even though well studied in three-dimensional (3D) configurations, only a few attempts have been reported to observe similar phenomena in twodimensional (2D) systems. This, however, is important to take advantage of photonic nanojets in integrated optical systems. Usually, surface plasmon polaritons are suggested for this purpose, but they suffer notoriously from the rather low propagation lengths due to intrinsic absorption. Here, we solve this problem and explore, theoretically, numerically, and experimentally, the use of Bloch surface waves sustained by a suitably structured all-dielectric media to enable subwavelength focusing in an integrated planar optical system. Since only a low index contrast can be achieved while relying on Bloch surface waves, we perceive a new functional element that allows a tight focusing and the observation of a photonic nanojet on top of the surface. We experimentally demonstrate a spot size of 0.66λ in the effective medium. Our approach paves the way to 2D alldielectric photonic chips for nano-particle manipulation in fluidic devices and sensing applications.

We present an original type of one-dimensional photonic crystal that includes one anisotropic layer made of a lithium niobate thin film. We demonstrate the versatility of such a device sustaining different Bloch surface waves (BSWs), depending on the orientation of the incident wave. By varying the orientation of the illumination of the multilayer, we measured an angle variation of 7° between the BSWs corresponding to the extraordinary and the ordinary index of the lithium niobate thin film. The potential of such a platform opens the way to novel tunable and active planar optics based on the electro- and thermo-optical properties of lithium niobate.