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Laser-induced formation of surface nanostructures is known for a long time. Responsible mechanisms, however, aie not completely understood. Early explanations were based on surface electromagnetic waves [1]. Alternative models were focused on self-organization of non-equilibrium surfaces via nonlinear feedback and material transport [2]. Investigations on volume structures in fused silica and glass...
We study surface plasmons on hexagonal hole arrays in gold on actively-pumped semiconductor. The observed dispersion yields the angle-dependent scattering. Lasing occurs in a radially-polarized donut beam and a hexagonal mode with mixed radial/azimuthal polarization.
Integration of multiple functions on an optical micro-chip is going to revolutionize the exploitation of optics for various applications such as communication, optical sensing, and biomedicine. One of the enabling functions is amplification at 1.5 μm [1]. Rare-earth-doped amplifiers typically deliver a net gain per unit length of only a few dB/cm [2]. In spiral-shaped channel waveguides a total internal...
In a biaxial biréfringent crystal there are two directions at which the refractive index surfaces intersect, leading to the phenomenon of conical refraction [1]. These conical intersections are analogs of Dirac points, and are generically present in non-chiral optical materials. One of the most interesting aspects of Dirac points is that they carry an associated topological charge. As such the propagation...
Controlling the interaction of light and matter is the basis for diverse applications ranging from light technology to quantum information processing. Nowadays, many of these applications are based on nanophotonic structures. It turns out that the confinement of light in such nanostructures imposes an inherent link between its local polarization and its propagation direction, also referred to as spin-momentum...
A current challenge and trend in optical sciences is to extend the toolbox generated from experiments with single emitters and single photons towards interfacing photons with a well-defined number of quantum emitters. The resulting complex optical network would enable studies of many-body quantum optical phenomena and could lend itself to quantum simulations. However, common light-matter interfaces...
Great attentions are drawn to usages of localized surface plasmon enhanced (LSP) optical fields to nonlinear plasmonics. In the previous study about the nonlinear plasmonics, the multiple photons in the LSP-enhanced fields were mixed by taking advantages of the nonlinearities of the metal surfaces. Here, we tried obtaining the additional increases in the nonlinearities on the metals surfaces by using...
Surface nano- and microstructuring with additive and subtractive lithography techniques are commonly used in nanotechnology and photonics, while nanoimprint lithography and nanosphere lithography are used for creating periodic structures for plasmonics applications. Single step, maskless optical patterning techniques also exist, notably multi-beam interference based techniques and Laser Induced Periodic...
It is well known that a thick scattering medium (e.g. a slab of paint) is opaque since incident waves are thoroughly scrambled [1, 2]. In the diffusive transport regime, the scattered light has an (ensemble-averaged) energy density that linearly increases with depth from the front surface to about one mean free path 1, and then decreases linearly with depth to the back surface. Two main questions...
Ultra-short pulse (USP) Laser Induced Periodic Surface Structures (LIPSS) namely ripples, micro-grooves and spikes [1] have received considerable attention since they can modify some key surface properties like wettability, colour and tribology, increasing the material's internal value [2]. Nevertheless, the complete understanding of the physical mechanisms leading to LIPSS formation is still under...
Indium Tin Oxide (ITO) is a highly conductive and transparent thin film used in modern technological applications; i.e organic light emitting devices (OLED) [1], transparent flat touch panel displays (FPD) [2], and solar cells [3]. Fast and highly precise selective patterning of ITO with controlled depth and width of scribed lines, is required for such applications. The pattering for such applications...
Colloidal nanocrystals (NCs) have attracted considerable attention in the field of light emitting devices thanks to their high fluorescence quantum yield and spectral tunability via electronic structure engineering and surface functionalization.[1, 2] Their composition and shape can be adjusted to obtain materials with tailored and stable optoelectronic properties. Surface functionalization allows...
Inspired by the idea of an artificial skin-like sensor structure, we develop fully integrated sensor networks in large-sized thin polymer foils. The project is part of collaborative research center “PlanOS-planar optronic systems”. One key aspect of such systems is to avoid electronic components as far as possible so that the quantities to be measured are directly converted into properties of light.
The development of mid-infrared (λ∼3–20 μm) integrated optical sensors has accelerated within the last years. The main driving interest is the potential of using photonic integrated elements capable of direct interaction with biomolecules and chemicals through their ground molecular vibrational modes, so that resonance fingerprints are exploited for novel sensor industrial applications. State-of-the-art...
In the last few years, several authors have reported the observation of a new class of acoustic waves in sub-wavelength diameter tapered optical fibers (TOFs) through Brillouin scattering [1, 2]. These include the observation of surface acoustic waves (SAW), hybrid shear and longitudinal acoustic waves (HAW) associated with anti-crossings (AC). It has also been suggested that these acoustic waves...
Silicon carbide (SiC) is a well-known material in the field of high temperature and high voltage electronics thanks to a high thermal conductivity, high electric field breakdown strength and high maximum current density [1]. Simultaneously with a strong inertness and a low thermal expansion, this makes silicon carbide a good material for extreme condition sensing [2]. The fact that the cubic structure...
Three years after the first realization [1] of the vertical external-cavity surface-emitting laser (VECSEL), passive mode locking by inserting a semiconductor saturable absorber mirror (SESAM) into the cavity was presented [2]. Besides the advantageous properties in continuous wave operation such as a near-diffraction limited beam profile and the possibility of bandgap engineering, SESAM mode-locked...
We report the first observation of highly confined polaritons with wavelength two orders of magnitude shorter than the free space wavelength that propagates on the surface of silicon carbide crystals covered by a few atomic layers of molybdenum disulfide.
Transformation optics makes use of coordinate transformations to explore the possibilities offered by artificially structured metamaterials for the manipulation of a wide variety of electromagnetic phenomena. Since a decade, transformation optics has consistently extended its scope. Initially, coordinate transformations were only applied to the transformation of light in the simplest of optical setups,...
Recently metal oxides have been introduced as promising materials for infrared and active plasmonics. By designing nanoantennas and metamaterials using transparent conducting oxides (TCOs), we can achieve strong light-matter interactions in the infrared while maintaining high transparency in the visible range. These properties have been used to design new types of infrared active surfaces for optical...
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