3889 results about "Photonic crystal" patented technology

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.

A CMOS compatible ten-gigabit-per-second region nano-waveguide included photonic communication link apparatus of low energy use per transmitted bit. An embodiment of the link includes an electrically pumped laser, an electro absorption modulator and a photodetector for the 1.5 to 2.0 micrometer infrared spectral region; omission of the separate electro absorption modulator is additionally disclosed. Each of these three nano-scale elements preferably includes active semiconductor crystal material situated in a preferably Silicon resonator within a nano-strip waveguide. The resonator is defined by dispersed resonator mirrors having tapered separation distance one dimensional photonic crystal lattice apertures of oxide holes or slots. Each of the three devices may be a semiconductor heterodiode pumped or controlled by laterally disposed wings enclosing the resonator to form a lateral PIN heterodiode for current injection or high E-field generation depending on bias and composition conditions selected.

PCT No. PCT/GB97/00817 Sec. 371 Date Apr. 13, 1998 Sec. 102(e) Date Apr. 13, 1998 PCT Filed Mar. 24, 1997 PCT Pub. No. WO97/36198 PCT Pub. Date Oct. 2, 1997An optical diffraction grating is formed from a region of photonic crystalline material Light is coupled into the photonic crystalline material, and the grazingly emergent output beam is collected. The photonic crystalline material may include an array of holes formed in a substrate of dielectric material, e.g., InP, and integrated with planar waveguide structures.

A high efficiency light emitting diode (LED) comprised of a substrate, a buffer layer grown on the substrate (if such a layer is needed), a first active region comprising primary emitting species (PES) that are electrically-injected, a second active region comprising secondary emitting species (SES) that are optically-pumped by the light emitted from the PES, and photonic crystals, wherein the photonic crystals act as diffraction gratings to provide high light extraction efficiency, to provide efficient excitation of the SES, and/or to modulate the far-field emission pattern.

A method of manufacturing a biopolymer photonic crystal includes providing a biopolymer, processing the biopolymer to yield a biopolymer matrix solution, providing a substrate, casting the matrix solution on the substrate, and drying the biopolymer matrix solution to form a solidified biopolymer film. A surface of the film is formed with a nanopattern, or a nanopattern is machined on a surface of the film. In another embodiment, a plurality of biopolymer films is stacked together. A photonic crystal is also provided that is made of a biopolymer and has a nanopatterned surface. In another embodiment, the photonic crystal includes a plurality of nanopatterned films that are stacked together.

A method of coupling a spliceable optical fibre for transmission of light in its longitudinal direction to an optical component, the method comprising (A) providing the spliceable optical fibre, said spliceable optical fibre comprising: (a) a core region (10, 20, 25, 30, 110); and (b) a microstructured cladding region, said cladding region surrounding said core region and comprising: (b1) an inner cladding region with inner cladding features (13, 22, 112) arranged in an inner cladding background material (11, 21, 111) with a refractive index n1, said inner cladding features comprising thermally collapsible holes or voids, and (b2) an outer cladding region with an outer cladding background material (12, 24, 114) with a refractive index n2; said spliceable optical fibre having at least one end; (B) collapsing said thermally collapsible holes or voids by heating said least one end of said spliceable optical fibre; and (C) coupling said collapsed spliceable optical fibre end to the optical component. A spliceable optical fibre; a preform for producing a spliceable optical fibre; a method of producing a spliceable optical fibre comprising drawing of the preform; a heat-treated spliceable optical fibre; an article comprising a spliceable optical fibre is further disclosed.

In an epitaxial structure of a solid state lighting system, electrical current injection into the active layer is used to excite the photon emission. The present invention employs a unique waveguide layer in the epitaxial structure for trapping the light generated by the active layer in the fundamental waveguide mode. Multiple photonic crystal regions with different characteristics located either outside or inside one or more current injection regions extract photons from the waveguide layer(s). The present invention creates solid state lighting with high optical output and high power efficiency.

This application describes a tunable photonic crystal device based on the electrical actuation of photonic crystal films. This device displays non-bleachable structural color, reflecting narrow bands of wavelengths tuned throughout the entire visible spectrum by expansion and contraction of the photonic crystal lattice

A method and apparatus use a photonic-crystal fiber having a very large core while maintaining a single transverse mode. In some fiber lasers and amplifiers having large cores problems exist related to energy being generated at multiple-modes (i.e., polygamy), and of mode hopping (i.e., promiscuity) due to limited control of energy levels and fluctuations. The problems of multiple-modes and mode hopping result from the use of large-diameter waveguides, and are addressed by the invention. This is especially true in lasers using large amounts of energy (i.e., lasers in the one-megawatt or more range). By using multiple small waveguides in parallel, large amounts of energy can be passed through a laser, but with better control such that the aforementioned problems can be reduced. An additional advantage is that the polarization of the light can be maintained better than by using a single fiber core.

Exemplary embodiments provide a scalable process for the growth of large scale and uniform III-N nanoneedle arrays with precise control of the position, cross sectional shape and/or dimensions for each nanoneedle. In an exemplary process, a plurality of nanoneedle array can be formed by growing one or more semiconductor material in a plurality of patterned rows of apertures with a predetermined geometry. The plurality of patterned rows of apertures can be formed though a thick selective nanoscale growth mask, which can later be removed to expose the plurality of nanoneedle arrays. The plurality of nanoneedle arrays can be connected top and bottom by a continuous coalesced epitaxial film, which can be used in a planar semiconductor process or be further configured as a photonic crystal to improve the output coupling of nanoscale optoelectronic devices such as LEDs and/or lasers.

A compressible photonic crystal comprising a polymer with an ordered array of voids, the photonic crystal having a reflectance in a first wavelength range for light incident to its incident surface and its opposing incident surface; wherein compression against at least a portion of at least one of the surfaces shifts the reflectance to a second wavelength range in at least that portion of that surface. The crystal may be used in authentication devices of various types.

A method for preparing electro-optical polymer-liquid crystal photonic crystals, comprising: disposing between at least two optically transparent electrode plates, a polymer-dispersed liquid crystal material that comprises, before exposure:

• • (a) a polymerizable monomer comprising at least one acrylate;
  • (b) a liquid crystal;
  • (c) a chain-extending monomer;
  • (d) a coinitiator;
  • (e) a photoinitiator; and
  • (f) a long chain aliphatic acid;
  • and exposing this polymer-dispersed liquid crystal material to light in an interference pattern.

A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts.

The present invention provides methods and compositions for authentication of articles and counterfeit deterrence using non-holographic micro-optics and microstructures having a surface relief greater than a few microns. Embodiments of the present invention disclose a range of distinctive optical effects obtained from micro-optic systems incorporating micro lenses, non-imaging collectors, prisms, wave guides, mirrors, gratings, structural interference filters, and photonic crystal microstructures.

A method and apparatus for reading a microbead having a code thereon is provided wherein the code is projected on and read from a Fourier plane. The microbead may be 1-1000 microns (um) or smaller in feature size. The code is projected on the Fourier plane by scattering input light off the microbead. The scattered light from the microbead is directed through an optical arrangement having a transform lens for projecting the code on the Fourier plane, and read on the Fourier plane using a charge coupled device (CCD) or other similar device. The code may include periodic layers of material having different refractivities or phase, including index of refraction differences; periodic spatial modulations having a different phase or amplitude; a periodic binary phase change used to code information in the Fourier plane; a photonic crystal used to encode the information on the microbead, wherein a pattern of holes causes interference between incident and scattered light to form spatial and spectral patterns in the far field that are unique to the pattern of holes; or may be formed in the microbead using a single photoactive inner region, a series of longitudinal holes, different fluorescence regions, or concentric rings of material in a preform.

A bistable photonic crystal configuration comprises a waveguide sided coupled to a single-mode cavity. This configuration can generate extremely high contrast between the bistable states in its transmission with low input power. All-optical switching action is also achieved in a nonlinear photonic crystal cross-waveguide geometry, in which the transmission of a signal can be reversibly switched on and off by a control input, or irreversibly switched, depending on the input power level.

A high efficiency, and possibly highly directional, light emitting diode (LED) with an optimized photonic crystal extractor. The LED is comprised of a substrate, a buffer layer grown on the substrate (if needed), an active layer including emitting species, one or more optical confinement layers that tailor the structure of the guided modes in the LED, and one or more diffraction gratings, wherein the diffraction gratings are two-dimensional photonic crystal extractors. The substrate may be removed and metal layers may be deposited on the buffer layer, photonic crystal and active layer, wherein the metal layers may function as a mirror, an electrical contact, and/or an efficient diffraction grating.

Light emission from a light package, such as from an LED light package, is enhanced by a system and method for adjusting the refractive index at the surface of the encapsulating material surrounding the light source. The surface refractive index is changed to better match the index within the encapsulating material with the index of the media surrounding the encapsulating material. In one embodiment, the index is adjusted by roughing the surface of the encapsulating material. In another embodiment, a separate layer is created having a corrective index of refraction. The separate layer can comprise photonic crystals, if desired. In some embodiments the adjusting will achieve a graded index of refraction.

A ring-laser system that includes a plurality of ring-laser gain elements and a spectral-beam-combining output stage configured to combine a plurality of beams coming from the gain elements into an output beam and that includes chromatic-dispersion compensation. In some embodiments, the output stage includes a plurality of highly reflective dielectric-coated focussing elements. In some embodiments, the output stage includes a plurality of high-efficiency dielectric-coated grating elements. In some embodiments, the output stage includes a mostly reflective but partially transmissive output mirror and a highly reflective beam-reversing mirror configured to reflect a majority of a backward-traveling signal beam such that it becomes forward traveling. In some embodiments, each gain element further includes a photonic-crystal-rod power amplifier. Some embodiments have an amplitude modulator configured to pulse the plurality of beams, and a timing controller configured to synchronize the pulses of the plurality of beams. Some embodiments further include a non-linear wavelength-conversion device.

The invention provides a method for fabricating planar waveguiding structures with embedded microchannels. The method includes the step of depositing, over a planar template having at least one indented feature comprising a ridge of a first optical material and a narrow trench adjacent thereto, a second optical material, and the step of subsequent annealing thereof, so that an embedded hollow microchannel forms within the trench. The method provides planar structures wherein the ridge and the embedded microchannel cooperate to form an optical waveguiding structure having a waveguiding direction collinear with the embedded microchannel. Embodiments of the method for forming microfluidic devices integrating ridge waveguides with hollow microchannels having surface access points for fluid delivery, and for forming photonic crystals, are disclosed together with corresponding device embodiments.

The present invention discloses a widely wavelength tunable polychrome colloidal photonic crystal device whose optical Bragg diffraction stop bands and higher energy bands wavelength, width and intensity can be tuned in a continuous and fine, rapid and reversible, reproducible and predictable fashion and over a broad spectral range by a controlled expansion or contraction of the colloidal photonic lattice dimension, effected by a predetermined change in the electronic configuration of the composite material. In its preferred embodiment, the material is a composite in the form of a film or a patterned film or shape of any dimension or array of shapes of any dimension comprised of an organized array of microspheres in a matrix of a cross-linked metallopolymer network with a continuously variable redox state of charge and fluid content. The chemo-mechanical and electro-mechanical optical response of the colloidal photonic crystal-metallopolymer gel is exceptionally fast and reversible, attaining its fully swollen state from the dry shrunken state and vice versa on a sub-second time-scale. These composite materials can be inverted by removal of the constituent microspheres from the aforementioned colloidal photonic crystal metallopolymer-gel network to create a macroporous metallopolymer-gel network inverse colloidal photonic crystal film or patterned film or shape of any dimension optical Bragg diffraction stop bands and higher energy bands wavelength, width and intensity can be redox tuned in a continuous and fine, rapid and reversible, reproducible and predictable fashion and over a broad spectral range by a controlled expansion or contraction of the colloidal photonic lattice dimensions.