Abstract: The present disclosure provides an optical waveguide design of a fiber modified with a thin layer of epsilon-near-zero (ENZ) material. The design results in an excitation of a highly confined waveguide mode in the fiber near the wavelength where permittivity of thin layer approaches zero. Due to the high field confinement within thin layer, the ENZ mode can be characterized by a peak in modal loss of the hybrid waveguide. Results show that such in-fiber excitation of ENZ mode is due to the coupling of the guided fundamental core mode to the thin-film ENZ mode. The phase matching wavelength, where the coupling takes place, varies depending on the refractive index of the constituents. These ENZ nanostructured optical fibers have many potential applications, for example, in ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and as subwavelength fluid channel for optical and bio-photonic sensing.

Abstract: The present disclosure provides devices, systems, circuits, and effective methods for advanced optical applications using plasmonics and ENZ materials. The disclosure provides for enhancement of the optical tunability of phase and amplitude of propagating plasmons, nonlinear-optical effects, and resonant network in optical fiber tip nanocircuits and integrates the tunable plasmonic and ENZ effects for in-fiber applications to provide optical fiber with high operating speed and low power consumption. The invention yields efficient coupling of a plasmonic functional nanocircuit on the facet of an optical fiber core. The invention also can use gate-tunable ENZ materials to electrically and nonlinear optically tune the plasmonic nanocircuits for advanced light manipulation. The invention efficiently integrates and manipulates the voltage-tuned ENZ resonance for phase and amplitude modulation in optical fiber nanocircuits.

Abstract: The present disclosure provides devices, systems, circuits, and effective methods for advanced optical applications using plasmonics and ENZ materials. The disclosure provides for enhancement of the optical tunability of phase and amplitude of propagating plasmons, nonlinear-optical effects, and resonant network in optical fiber tip nanocircuits and integrates the tunable plasmonic and ENZ effects for in-fiber applications to provide optical fiber with high operating speed and low power consumption. The invention yields efficient coupling of a plasmonic functional nanocircuit on the facet of an optical fiber core. The invention also can use gate-tunable ENZ materials to electrically and nonlinear optically tune the plasmonic nanocircuits for advanced light manipulation. The invention efficiently integrates and manipulates the voltage-tuned ENZ resonance for phase and amplitude modulation in optical fiber nanocircuits.

Abstract: The present disclosure provides an optical waveguide design of a fiber modified with a thin layer of epsilon-near-zero (ENZ) material. The design results in an excitation of a highly confined waveguide mode in the fiber near the wavelength where permittivity of thin layer approaches zero. Due to the high field confinement within thin layer, the ENZ mode can be characterized by a peak in modal loss of the hybrid waveguide. Results show that such in-fiber excitation of ENZ mode is due to the coupling of the guided fundamental core mode to the thin-film ENZ mode. The phase matching wavelength, where the coupling takes place, varies depending on the refractive index of the constituents. These ENZ nanostructured optical fibers have many potential applications, for example, in ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and as subwavelength fluid channel for optical and bio-photonic sensing.

Abstract: The present disclosure provides devices, systems, circuits, and effective methods for advanced optical applications using plasmonics and ENZ materials. The disclosure provides for enhancement of the optical tunability of phase and amplitude of propagating plasmons, nonlinear-optical effects, and resonant network in optical fiber tip nanocircuits and integrates the tunable plasmonic and ENZ effects for in-fiber applications to provide optical fiber with high operating speed and low power consumption. The invention yields efficient coupling of a plasmonic functional nanocircuit on the facet of an optical fiber core. The invention also can use gate-tunable ENZ materials to electrically and nonlinear optically tune the plasmonic nanocircuits for advanced light manipulation. The invention efficiently integrates and manipulates the voltage-tuned ENZ resonance for phase and amplitude modulation in optical fiber nanocircuits.

Abstract: The present disclosure provides a system and method for an ultrathin optical metasurface with an array patterning formed on an optical fiber facet that enables manipulation of light passing therethrough, such as focusing and steering the light, and controlling a polarization state of light. The patterning can be non-uniform to selectively direct light passing through the metasurface. Array structures can vary in size, angle, shapes, and other non-uniform aspects. Further, the array can include materials that can be electrically activated and controlled to variably tune the metasurface characteristics for increased ability to manipulate the light passing therethrough. The materials can include a conductor, a dielectric, or a composite of a conductor, insulator, and dielectric formed on the optical fiber.

Abstract: The present disclosure provides an optical waveguide design of a fiber modified with a thin layer of epsilon-near-zero (ENZ) material. The design results in an excitation of a highly confined waveguide mode in the fiber near the wavelength where permittivity of thin layer approaches zero. Due to the high field confinement within thin layer, the ENZ mode can be characterized by a peak in modal loss of the hybrid waveguide. Results show that such in-fiber excitation of ENZ mode is due to the coupling of the guided fundamental core mode to the thin-film ENZ mode. The phase matching wavelength, where the coupling takes place, varies depending on the refractive index of the constituents. These ENZ nanostructured optical fibers have many potential applications, for example, in ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and as subwavelength fluid channel for optical and bio-photonic sensing.

Abstract: The present disclosure provides a system and method for a tunable ENZ material that can vary the absorption of radiant energy. The tunable ENZ material can act as a broadband absorber advantageously using a stack of ultrathin conducting layers having an epsilon-near-zero (ENZ) regime of permittivity at different wavelengths. The conducting materials can include at least partially transparent conducting oxide or transition metal nitride layers with different electron concentrations and hence different ENZ frequencies for a broadband range of energy absorption. The layer(s) can be directly tuned to various frequencies to achieve high levels of absorption at deep subwavelength ENZ thicknesses. An applied electric bias can create electron accumulation/depletion regions in an ENZ semiconductor device and allows control of plasma frequency and hence high levels of absorption in the device. Further, for a stack of layers, the carrier concentration can be altered from layer to layer.

Abstract: The present disclosure provides a system and method for an ultrathin optical metasurface with an array patterning formed on an optical fiber facet that enables manipulation of light passing therethrough, such as focusing and steering the light, and controlling a polarization state of light. The patterning can be non-uniform to selectively direct light passing through the metasurface. Array structures can vary in size, angle, shapes, and other non-uniform aspects. Further, the array can include materials that can be electrically activated and controlled to variably tune the metasurface characteristics for increased ability to manipulate the light passing therethrough. The materials can include a conductor, a dielectric, or a composite of a conductor, insulator, and dielectric formed on the optical fiber.

Abstract: The present disclosure provides a system and method for a fiber-coupled, metal-tip chemical imaging spectroscopy. The system couples the electromagnetic radiation (EMR), such as laser light, through an optical fiber to a conductive tip for both EMR excitation to the sample through the conductive tip and EMR signal collection from the sample through the conductive tip. The system and method effectively eliminates the need for an optical alignment between the EMR source and the tip, and still offers the customary spatial resolution of a non-coupled system.

Abstract: The present disclosure provides a system and method for a tunable ENZ material that can vary the absorption of radiant energy. The tunable ENZ material can act as a broadband absorber advantageously using a stack of ultrathin conducting layers having an epsilon-near-zero (ENZ) regime of permittivity at different wavelengths. The conducting materials can include at least partially transparent conducting oxide or transition metal nitride layers with different electron concentrations and hence different ENZ frequencies for a broadband range of energy absorption. The layer(s) can be directly tuned to various frequencies to achieve high levels of absorption at deep subwavelength ENZ thicknesses. An applied electric bias can create electron accumulation/depletion regions in an ENZ semiconductor device and allows control of plasma frequency and hence high levels of absorption in the device. Further, for a stack of layers, the carrier concentration can be altered from layer to layer.

Abstract: The present disclosure provides a system and method for a fiber-coupled, metal-tip chemical imaging spectroscopy. The system couples the electromagnetic radiation (EMR), such as laser light, through an optical fiber to a conductive tip for both EMR excitation to the sample through the conductive tip and EMR signal collection from the sample through the conductive tip. The system and method effectively eliminates the need for an optical alignment between the EMR source and the tip, and still offers the customary spatial resolution of a non-coupled system.