Richa Dubey

Near-field characterization of a Bloch-surface-wave-based 2D disk resonator.

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.

Ultra-thin Bloch-surface-wave-based reflector at telecommunication wavelength

We experimentally demonstrate the optical properties of gratings engraved in a single-mode waveguide fabricated on top of a dielectric multilayer platform. The structure can be approached as a reflector for Bloch-surface-wave-based two-dimensional optical systems. The gratings have been fabricated on a thin (∼λ/25) titanium dioxide layer with a thickness of a few tens of nanometers deposited on the top of a multilayer platform. The optical properties of the gratings have been characterized in the near field with the aid of multi-heterodyne scanning near-field optical microscopy. We investigate the surface wave’s interference pattern, produced by incident and reflected light in front of the gratings. The presented gratings behave as an efficient Bloch-surface–wave-based reflector at telecommunication wavelength.

Near-field investigation of Bloch surface wave based 2D optical components

We study the Bloch surface wave based nano-thin 2D optical components. The 2D elements are fabricated on the dielectric multilayer platform which sustains the Bloch surface waves. Such a platform is considered as a novel foundation for planar integrated optics. We exploit the total internal reflection configuration to achieve the phase matching condition for BSW excitation. Because of the evanescent behavior of the BSW, we use a scanning near field optical microscope to characterize the near-field properties of in-plane components. The 2D optical components include Disk resonators and Bessel-like beams.

Bloch surface waves, a 2D platform for planar optical integration

A novel platform suitable for fundamental investigations of light propagation through micro- and nano-structures will be discussed. This platform is based on a dielectric multilayer that sustains Bloch surface waves (BSWs). BSWs are electromagnetic surface waves excited at the interface between a truncated periodic dielectric multilayer and a surrounding media. The modification of the top surface to customize a complete 2D micro-system can be produced using e-beam writing, optical lithography or other patterning techniques. The results obtained confirm the possibility of developing a robust multilayer platform that would pave the way for integration of photonic components in photonic chips using standard wafer-scale production.

Optics in 2D, Bloch surface wave phenomena and applications

Nano-photonics, where optical structures can manipulate light at the sub-wavelength scale, is making important advances towards optical communications, imaging and sensing. A novel platform suitable for fundamental investigations of light propagation through micro- and nano-structures will be discussed. This platform is based on a dielectric multilayer that sustains Bloch surface waves (BSWs). We experimentally and theoretically investigate components including a disk resonator and a photonic nanojet, which are fabricated on a Bloch surface wave platform.

Nano-thin 2D axicon generating nondiffracting surface waves

We investigate nondiffracting surface waves. On top of the Bloch surface wave platform, a 60-nm-thick TiO2 isosceles triangle serves as a 2D axicon. Scanning near-field microscopy measurements verify nondiffracting surface beam properties.

Nondiffracting Bloch surface wave: 2D quasi-Bessel-Gauss beam

2D Bessel-Gauss beam, which is known as nondiffracting beams in 3D space, is demonstrated in the domain of Bloch surface wave. Its self-healing capacity is verified by using cylindrical obstacles in the diffraction-free beam path.

Waveguide grating as a Bragg mirror on Bloch surface waves based platform for 2D integrated optics applications

We study and demonstrate a Bloch-surface-wave-based nano-thin waveguide grating. The waveguide grating is characterized as a Bragg mirror at telecommunication wavelengths. The structure is a dielectric multilayer platform designed to sustain a Bloch surface wave. Such a platform is regarded as a foundation for in-plane integrated optics. The Kretschmann coupling configuration, as the most widely used approach, is utilized to excite the optical surface waves. We use multi-heterodyne scanning near-field optical microscopy to characterize the waveguide gratings in the near-field. The fabricated waveguide grating shows the expected Bragg mirror behavior with a measured reflectivity of approximately 72 % inside the photonic band gap at λ = 1553 nm.