Abstract: A coupling element includes a first stage having a dielectric waveguide that is transitioned to a waveguide having a sequence of resonators with a fixed period. A second stage transitions the waveguide to a photonic crystal waveguide by gradually bringing closer at an angle the cladding bulk of the photonic crystal to the waveguide.

Abstract: A photonic crystal includes a plurality of photonic crystal slabs that is suited for confining TE polarizations and TM polarizations. The photonic crystal slabs include alternating slabs of dielectric rods and air holes. The alternating slabs create a lateral symmetry plane. The alternating slabs of dielectric rods and air holes further include planar line defects resulting in the formation of defect bands inside the bandgap of the photonic crystal.

Abstract: A photonic crystal optical switch having a periodic dielectric structure including at least one input waveguide. First and second waveguide arms branch from the input waveguide in which the relative optical path lengths of electromagnetic radiation within the arms are controlled by stimuli. At least one output waveguide that combines the electromagnetic radiation propagating within the first and second waveguide arms.

Abstract: Optical components including a laser based on a dielectric waveguide extending along a waveguide axis and having a refractive index cross-section perpendicular to the waveguide axis, the refractive index cross-section supporting an electromagnetic mode having a zero group velocity for a non-zero wavevector along the waveguide axis.

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: Techniques for monitoring the quality (e.g., optical and mechanical properties) in optical waveguides (e.g., photonic crystal fibers) are disclosed. Additionally, techniques for detecting and localizing defects in the waveguides are also described. Pulses of light are launched into one end of an optical waveguide. The amount of light scattered out of the same end of the waveguide (i.e., a backscattered or reflected signal) is monitored at certain wavelengths specific to the spectral characteristics of the waveguide. Transmission characteristics and defect localization can be determined from the backscattered signal.

Abstract: A system for exhibiting Cherenkov radiation is provided. The system includes a beam of charged particles. A photonic crystal structure receives said beam of charged particles. The charged particles moves in said photonic crystal structure so that Cherenkov radiation is produced at all velocities without requiring resonances in the effective material constants of said photonic crystal structure.

Abstract: Techniques for monitoring optical waveguides are disclosed.

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: 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: A coupling element includes a first stage having a dielectric waveguide that is transitioned to a waveguide having a sequence of resonators with a fixed period. A second stage transitions the waveguide to a photonic crystal waveguide by gradually bringing closer at an angle the cladding bulk of the photonic crystal to the waveguide.

Abstract: A system for exhibiting Cherenkov radiation is provided. The system includes a beam of charged particles. A photonic crystal structure receives said beam of charged particles. The charged particles moves in said photonic crystal structure so that Cherenkov radiation is produced at all velocities without requiring resonances in the effective material constants of said photonic crystal structure.

Abstract: A photonic crystal waveguide having multiple guided modes, the waveguide comprising: a dielectric confinement region surrounding a waveguide axis, the confinement region comprising a photonic crystal having at least one photonic band gap, during operation the confinement region guides EM radiation in a first range of frequencies to propagate along the waveguide axis; a dielectric core region extending along the waveguide axis and surrounded by the confinement region about the waveguide axis; and a mode coupling segment comprising at least one bend in the waveguide axis, wherein during operation the mode coupling segment converts EM energy in a first guided mode to a second guided mode with a conversion efficiency greater than 10% for a frequency in the first range of frequencies.

Abstract: A photonic bandgap microcavity is provided. The microcavity includes a membrane structure that can experience strain. A photonic bandgap waveguide element is formed on the membrane structure having a defect so that when the membrane structure is strained, the photonic bandgap waveguide element is tuned to a selective amount.

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 bi-stable switch includes a photonic crystal cavity structure using its photonic crystal properties to characterize a bi-stable switch so that optimal control is provided over input and output of the switch. A plurality of waveguide structures are included, at least one of the waveguide structures providing the input to the switch and at least one providing the output to the switch.

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: A periodic electromagnetic medium is disclosed that includes a surface that provides an interface with an ambient medium and a periodic structure that provides negative refraction within the medium of an incident electromagnetic field incident on the surface. In various embodiments the incident electromagnetic field is within a range of frequencies, the medium may include dielectric or metallic material, and has either a positive or negative effective index.