Related papers: Overcoming the tradeoff between confinement and fo…
This study presents a prospective concept of a mechanically reconfigurable Gradient Index (GRIN) lens for focusing and beamforming applications. The lens is formed by corrugated layers, each realizing a refractive index profile expressed in…
Many works in elasticity have exploited the concept of gradient index (GRIN) lenses, borrowed from optics, for wave focusing and control. These effects are particularly attractive for cloaking, absorption or energy harvesting applications.…
We report an inhomogeneous acoustic metamaterial lens based on spatial variation of refractive index for broadband focusing of underwater sound. The index gradient follows a modified hyperbolic secant profile designed to reduce aberration…
Light can be confined transversely and delivered axially in a waveguide. However, waveguides are lossy static structures whose modal characteristics are fundamentally determined by the boundary conditions, and thus cannot be readily changed…
In this work, we present the design of cycloidal waveguides from a gradient refractive index (GRIN) medium in analogy to the fastest descending problem in classical mechanics. Light rays propagate along cycloids in this medium, of which the…
In this paper, a novel gradient index (GRIN) structural lens based on the concept of generalized Luneburg lens (GLL) is proposed. This lens allows for the realization of double foci and localization of energy flow between the two focal…
Biomedical applications requiring tissue diagnosis, activation, and treatment could be substantially leveraged by optical methods, owing to their unique feature set. However, their widespread application is severely limited by the strong…
We present the design, simulation, and planned fabrication process of a flat high resistivity silicon gradient index (GRIN) lens for millimeter and submillimeter wavelengths with very low absorption losses. The gradient index is created by…
The symmetry matching between the source and the lens results of fundamental interest for lensing applications. In this work we have modeled an axisymmetric gradient index (GRIN) lens made of rigid toroidal scatterers embedded in air…
Remote focusing of light in a graded-index medium via mode interference is demonstrated using exact analytical solutions of the wave equation. Strong focusing of light occurs at extremely long distances and it revivals periodically with…
Optical imaging through scattering media is a fundamental challenge in many applications. Recently, substantial breakthroughs such as imaging through biological tissues and looking around corners have been obtained by the use of…
Confining light illumination in the three dimensions of space is a challenge for various applications. Among these, optogenetic methods developed for live experiments in cell biology would benefit from such a localized illumination as it…
The integration of nanoscale electronics with conventional optical devices is restricted by the diffraction limit of light. Metals can confine light at the subwavelength scales needed, but they are lossy, while dielectric materials do not…
Even though submicron silicon waveguides have been proposed for dense integration of photonic devices, to date the lightwave circuits on the market mainly rely on waveguides with micron-scale core dimensions. These larger waveguides feature…
Focusing light into opaque random or scattering media such as biological tissue is a much sought-after goal for biomedical applications such as photodynamic therapy, optical manipulation, and photostimulation. However, focusing with…
We report the observation of transient nonlinear optical effects in a macroscopic whispering gallery mode resonator made of rutile TiO$_2$, demonstrating strong optical-microwave transduction under laser irradiation. By comparing the…
We propose a class of waveguides operating near cutoff such that electromagnetic energy is mainly bound to the cladding rather than the dielectric core to achieve subdiffraction confinement of light. The cladding incorporates an alternating…
This study reports the successful fabrication of high-positive refractive index change waveguides, exceeding 0.02 in fluoride glasses, marking a significant advancement in integrated optical components for visible to mid-infrared…
The use of artificial gauge fields enables systems of uncharged particles to behave as if affected by external fields. Generated by geometry or external modulation, artificial gauge fields have been instrumental in demonstrating topological…
Integrated optical devices able to control light matter interactions on the nanoscale have attracted the attention of the scientific community in recent years. However, most of these devices are based on silicon waveguides, limiting their…