Abstract: A method for fabricating a terahertz waveguide comprises forming a multilayer reflector formed of alternating layers of first and second polymer materials with distinct refractive indices, and defining with the multilayer reflector a hollow core through which terahertz radiation propagates. The corresponding terahertz waveguide comprises the multilayer reflector formed of the alternating layers of the first and second polymer materials with distinct refractive indices, and a hollow core defined by the multilayer reflector and through which terahertz radiation propagates.

Abstract: A sensor and method for surface plasmon resonance sensing, wherein a small variation of the refractive index of an ambient medium results in a large variation of loss of a sensing mode. The surface plasmon resonance sensor comprises an antiguiding waveguide including a core characterized by a refractive index and a reflector surrounding the core. The reflector has an external surface and is characterized by a band gap and a refractive index higher than the refractive index of the core. A coating is deposited on the external surface of the core, the coating defining with the ambient medium a coating/ambient medium interface. In operation, the coating is in contact with the ambient medium, and the antiguiding waveguide is supplied with an electromagnetic radiation to (a) propagate a mode for sensing having an effective refractive index lower than the refractive index of the core and higher than a refractive index of an ambient medium and (b) produce surface plasmons at the coating/ambient medium interface.

Abstract: A sensor and method for surface plasmon resonance sensing, wherein a small variation of the refractive index of an ambient medium results in a large variation of loss of a sensing mode. The surface plasmon resonance sensor comprises an antiguiding waveguide including a core characterized by a refractive index and a reflector surrounding the core. The reflector has an external surface and is characterized by a band gap and a refractive index higher than the refractive index of the core. A coating is deposited on the external surface of the core, the coating defining with the ambient medium a coating/ambient medium interface. In operation, the coating is in contact with the ambient medium, and the antiguiding waveguide is supplied with an electromagnetic radiation to (a) propagate a mode for sensing having an effective refractive index lower than the refractive index of the core and higher than a refractive index of an ambient medium and (b) produce surface plasmons at the coating/ambient medium interface.

Abstract: In general, in one aspect, the invention features an apparatus that includes a photonic crystal fiber configured to guide a mode of electromagnetic radiation at a wavelength, ?, along a waveguide axis. The fiber includes a core extending along the waveguide axis, and a confinement region extending along the waveguide axis and surrounding the core. The confinement region includes alternating layers of a first and a second dielectric material having thicknesses d1 and d2 and different refractive indices n1 and n2, respectively. The thickness of at least one of the alternating layers of the first material differs from thickness d1QW or at least one of the alternating layers of the second material differs from thickness d2QW, where d1QW and d2QW correspond to a quarter-wave condition for the two dielectric materials given by d1QW=?/(4?{square root over (n12?1)}) and d2QW=?/(4?{square root over (n22?1)}), respectively.

Abstract: A device for converting frequency of electromagnetic radiation includes a nonlinear medium that forms a moving grating in the nonlinear medium by introducing at opposite ends of the nonlinear medium a first set of electromagnetic radiation having varying frequencies. Electromagnetic radiation is inputted into the nonlinear medium at a first frequency and extracted at a second frequency from the nonlinear medium. The moving grating in the nonlinear medium allows for electromagnetic radiation to be converted into the second frequency.

Abstract: An optical waveguide including: a dielectric core region extending along a waveguide axis; and a dielectric confinement region surrounding the core about the waveguide axis, the confinement region comprising a photonic crystal structure having a photonic band gap, wherein during operation the confinement region guides EM radiation in at least a first range of frequencies to propagate along the waveguide axis, wherein the core has an average refractive index smaller than about 1.3 for a frequency in the first range of frequencies, and wherein the core a diameter in a range between about 4? and 80?, wherein ? is a wavelength corresponding to a central frequency in the first frequency range.

Abstract: In general, in one aspect, the invention features an apparatus that includes a photonic crystal fiber configured to guide a mode of electromagnetic radiation at a wavelength, ?, along a waveguide axis. The fiber includes a core extending along the waveguide axis, and a confinement region extending along the waveguide axis and surrounding the core. The confinement region includes alternating layers of a first and a second dielectric material having thicknesses d1 and d2 and different refractive indices n1 and n2, respectively. The thickness of at least one of the alternating layers of the first material_differs from thickness d1QW or at least one of the alternating layers of the second material_differs from thickness d2QW, where d1QW and d2QW correspond to a quarter-wave condition for the two dielectric materials given by d1QW=?/(4{square root}{square root over (n12?1)}) and d2QW=?/(4{square root}{square root over (n22?1)}), respectively.

Abstract: By judicious engineering of grating parameters such as tooth shape, duty cycle and phase offset, the grating strengths and effective indices of the polarization modes of a grated waveguide are adjusted over a wide range of values to achieve a desired level of polarization sensitivity, or insensitivity. In the typical example, the physical geometry of the grating teeth is adjusted so that degenerate behavior (nTE=nTM and ?TE=?TM) is obtained for two polarization modes; the effective refractive indices and grating strengths are matched for the TE and TM polarization modes. In the current embodiment the sidewall gratings are used in which the tooth profile is selected in order to equalize the grating strength for each polarization mode.

Abstract: High index-contrast fiber waveguides, materials for forming high index-contrast fiber waveguides, and applications of high index-contrast fiber waveguides are disclosed.

Abstract: An optical waveguide having a working mode with a tailored dispersion profile, the waveguide including: (i) a dielectric confinement region surrounding a waveguide axis, the confinement region comprising a photonic crystal having at least one photonic bandgap, wherein during operation the confinement region guides EM radiation in a first range of frequencies to propagate along the waveguide axis; (ii) a dielectric core region extending along the waveguide axis and surrounded by the confinement region about the waveguide axis, wherein the core supports at least one guided mode in the first frequency range; and (iii) a dielectric dispersion tailoring region surrounded by the confinement region about the waveguide axis, wherein the dispersion tailoring region introduces one or more additional modes in the first range of frequencies that interact with the guided mode to produce the working mode.

Abstract: A device for converting frequency of electromagnetic radiation includes a nonlinear medium that forms a moving grating in the nonlinear medium by introducing at opposite ends of the nonlinear medium a first set of electromagnetic radiation having varying frequencies. Electromagnetic radiation is inputted into the nonlinear medium at a first frequency and extracted at a second frequency from the nonlinear medium. The moving grating in the nonlinear medium allows for electromagnetic radiation to be converted into the second frequency.

Abstract: High index-contrast fiber waveguides, materials for forming high index-contrast fiber waveguides, and applications of high index-contrast fiber waveguides are disclosed.

Abstract: In general, in one aspect, the invention features a waveguide that includes a first portion extending along a waveguide axis including a first chalcogenide glass, and a second portion extending along the waveguide axis including a second chalcogenide glass, wherein the second chalcogenide glass is different from the first chalcogenide glass.

Abstract: Electromagnetic radiation is input into a photonic crystal having a shock wave propagating within, wherein interactions between the shock wave and the incident electromagnetic radiation provide for the modification of frequency and bandwidth associated with input electromagnetic radiation. Modifications in frequency of the electromagnetic radiation are on the order,of the gap size with 100% efficiency in some cases. Additionally, the bandwidth associated with the electromagnetic radiation is increased or decreased by orders of magnitude based on such interactions. High amplitudes are trapped at the shock front for a controllable period of time, allowing for the controlled manipulation of pulses of light. Lastly, the incorporation of deliberately designed crystal defects and non-linear materials results in the conversion of all the energy in the defect band upwards in frequency if the highest group velocity is less than the shock wave speed.

Abstract: An optical waveguide including: a dielectric core region extending along a waveguide axis; and a dielectric confinement region surrounding the core about the waveguide axis, the confinement region comprising a photonic crystal structure having a photonic band gap, wherein during operation the confinement region guides EM radiation in at least a first range of frequencies to propagate along the waveguide axis, wherein the core has an average refractive index smaller than about 1.3 for a frequency in the first range of frequencies, and wherein the core a diameter in a range between about 4&lgr; and 80&lgr;, wherein &lgr; is a wavelength corresponding to a central frequency in the first frequency range.

Abstract: An optical waveguide including: a dielectric core region extending along a waveguide axis; and a dielectric confinement region surrounding the core about the waveguide axis, the confinement region comprising a photonic crystal structure having a photonic band gap, wherein during operation the confinement region guides EM radiation in at least a first range of frequencies to propagate along the waveguide axis, wherein the core has an average refractive index smaller than about 1.3 for a frequency in the first range of frequencies, and wherein the core a diameter in a range between about 4 &lgr; and 80 &lgr;, wherein &lgr; is a wavelength corresponding to a central frequency in the first frequency range.

Abstract: By judicious engineering of grating parameters such as tooth shape, duty cycle and phase offset, the grating strengths and effective indices of the polarization modes of a grated waveguide are adjusted over a wide range of values to achieve a desired level of polarization sensitivity, or insensitivity. In the typical example, the physical geometry of the grating teeth is adjusted so that degenerate behavior (nTE=nTM and &kgr;TE=&kgr;TM) is obtained for two polarization modes; the effective refractive indices and grating strengths are matched for the TE and TM polarization modes. In the current embodiment the sidewall gratings are used in which the tooth profile is selected in order to equalize the grating strength for each polarization mode.

Abstract: High index-contrast fiber waveguides, materials for forming high index-contrast fiber waveguides, and applications of high index-contrast fiber waveguides are disclosed.

Abstract: High index-contrast fiber waveguides, materials for forming high index-contrast fiber waveguides, and applications of high index-contrast fiber waveguides are disclosed.

Abstract: High index-contrast fiber waveguides, materials for forming high index-contrast fiber waveguides, and applications of high index-contrast fiber waveguides are disclosed.