Abstract: An optical planar waveguide comprising erbium-doped silica glass has an active core with a length of not less than 5 cm, typically in a range of 0.2 cm to 100 meters, preferably 0.5 cm to 5 meters. Preferably, the active core of the planar waveguide has a serpentine shape. The radius of curvature of the serpentine planar waveguide is in a range of about 0.1 mm to 50 mm, preferably about 20 mm. The erbium-doped silica glass has a low concentration of erbium atoms, corresponding to an Er/Si atomic ratio in a range of 10−5 to 2×10−3, preferably in a range of about from 5×10−5 to 3×10−4. A layer of erbium-doped silica glass having a low concentration of erbium is formed on a substrate by sublimating a solid source of an erbium-containing metal organic precursor compound, mixing vaporized molecules of the precursor with other gases for forming silica glass, and: generating a plasma in the reaction mixture.

Abstract: The present invention relates to an optical device comprising an ionic conductor and a pair of electrodes, the ionic conductor being made of a material that is transparent to light and contains mobile ions and the electrodes being suitable for absorbing and desorbing the ions and being in ionic contact with the ionic conductor. The refractive index in at least a zone of the ionic conductor can be varied under the effect of the voltage applied between the electrodes. The electrodes contain an electrochemically active material selected from an active carbon, a conductive polymer, and an insertion material suitable for inserting ions in its structure.

Abstract: A co-doped silicate optical waveguide having a core including silica, and oxides of aluminum, germanium, erbium and thulium. The composition concentrations are: Er from 15 ppm to 3000 ppm; Al from 0.5 mol % to 12 mol %; Tm from 15 ppm to 10000 ppm; and Ge from 1 mol % to 20 mol %. In a specific embodiment, the concentration of Er is from 150 ppm to 1500 ppm; Al is from 2 mol % to 8 mol %; and Tm is from 15 ppm to 3000 ppm. A boron-less cladding surrounds the core.

Abstract: The present invention relates to an optical fiber and a planar waveguide for achieving a uniform optical attenuation, which comprises a core co-doped with a first metal ions having an optical absorption coefficient of a negative slope in a particular wavelength band and a second metal ions having an optical absorption coefficient of a positive slope in a predetermined wavelength band.

Abstract: The present invention relates in general to optical waveguide devices, which preferably are planar, e.g., optical arrayed waveguide gratings (AWGs), multiplexers/demultiplexers, optical add/drop multiplexers and the like. More particularly, the present invention provides integrated optical waveguide devices having central wavelengths (or channel wavelengths) which are temperature insensitive in that they do not or do almost not shift upon temperature variations in the environment. Such devices are also called athermalized or athermal devices. Preferably, most or all parts of such devices including waveguides, cladding material and the substrate itself consist of organic polymeric materials. The devices of the invention substantially remedy the problems encountered with the limitations and disadvantages of common devices as known in the prior art.

Abstract: The present invention concerns waveguides made from porous glass which have been doped with certain selected materials which exhibit optical properties. In the context of the invention, the selected materials are optical materials which exhibit optical activity or a Faraday effect, such as an electro-optic material, and more specifically a polymer. Devices made according to the present invention can be used as phase modulators.

Abstract: Featured is a high power, broadband superfluorescent source with very low relative intensity noise (RIN) including a seed source, a modulator operably coupled to the seed source and a polarization maintaining (PM) amplifier operably coupled to the modulator. The output of the seed source is processed in the modulator so the modulator outputs a polarized optical output to the PM amplifier. The PM amplifier amplifies the modulated, polarized optical output so as to provide an amplified polarized optical output therefrom. Also featured is a feedback circuit operably coupled to the PM amplifier to control the transmission of the modulator so as to minimize the amplitude fluctuations in the output signal. Such a source is advantageous in high precision fiber optical rotation sensors and multiplexed strain sensing arrays.

Abstract: A tellurite-based glass composition for use in EDFAs exhibits higher phonon energy without sacrificing optical, thermal or chemical durability properties. The introduction of boron oxide (B2O3) into the Er3+-doped tellurite glasses increases the phonon energy from typically 785 cm−1 up to 1335 cm−1. The inclusion of additional glass components such as Al2O3 has been shown to enhance the thermal stability and particularly the chemical durability of the boro-tellurite glasses. Er:Yb codoping of the glass does further enhance its gain characteristics.

Abstract: An electro-optic waveguide device, comprising (a) a first polymer buffer clad having a refractive index of about 1.445 to about 1.505 and a thickness of about 2.2 &mgr;m to about 3.2 &mgr;m; (b) a first polymer clad having a refractive index of about 1.53 to about 1.61 and a thickness of about 1.0 &mgr;m to about 3.0 &mgr;m; (c) an electro-optic polymer core having a refractive index of about 1.54 to about 1.62 and a thickness of about 1.0 &mgr;m to about 3.0 &mgr;m; and (d) a second polymer buffer clad having a refractive index of about 1.445 to about 1.505 and a thickness of about 2.2 &mgr;m to about 3.2 &mgr;m.

Abstract: A polymer-based waveguide device is for use in an optical amplifier or as a laser waveguide. The waveguide device includes a substrate (1), a polymer bottom cladding layer (21) on the substrate, a polymer channel waveguide (3) on the bottom cladding layer, and a polymer top cladding layer (22). The channel waveguide is doped with at least one kind of rare earth metal ion that can be excited to produce a laser. The bottom and top cladding layers have a same refractive index, which is substantially lower than a refractive index of the channel waveguide. When a light signal is input to the waveguide device, an amplified light signal is obtained and is transmitted within the channel waveguide.

Abstract: An optical fiber-based device exhibiting tunable birefringence utilizes a section of fiber including an optically nonlinear core region (i.e., doped with a material such as vanadium or erbium), where the fiber is configured to exhibit circular asymmetry and thus introduce birefringence into the fiber. The circular asymmetry may be accomplished by depositing the nonlinear core material in an asymmetric pattern or by launching the pump signal into an asymmetric mode of the fiber waveguide (i.e., an LP[1,m] mode). Polarization control can be generated by such a device through controlling the intensity of an input optical pump signal, since the pump signal intensity has been found to control the birefringence of a circularly asymmetric fiber waveguide.

Abstract: An optical fiber comprises a photosensitive core that includes a concentration of a first material that increases the refractive index of the core and a concentration of a second material that is other than boron and that reduces the refractive index of the core. A cladding is disposed about the core for tending to confine light to the core. The fiber also includes at least one longitudinally extending region having a thermal coefficient of expansion that is different from the thermal coefficient of expansion of the cladding. In another embodiment, the core includes a concentration of germanium and a concentration of boron. Also disclosed is a polarization-maintaining double-clad (PM DC) fiber comprising one or both of at least one circular axially extending stress inducing region(s) and an inner cladding comprising a circular outer perimeter.

Abstract: Optical fiber preforms can comprise a glass preform structure with an inner cavity. A powder can be placed within the inner cavity having an average primary particle size of less than about one micron. The powder can be in the form of an unagglomerated particles or a powder coating with a degree of agglomeration or hard fusing ranging from none to significant amounts as long as the primary particles are visible in a micrograph. Powders can be placed within a preform structure by forming a slurry with a dispersion of submicron/nanoscale particles within a cavity within the prefrom. In other embodiments, a powder coating is formed within a preform structure by depositing the powder coating directly from a reaction product stream. The formation of the powder coating can be formed within the reaction chamber or outside of the reaction chamber by flowing the product particle stream through a conduit leading to the preform structure. In additional embodiments, a powder coating is placed on an insert, e.g.

Abstract: An optical waveguide including a core having silica, Al, a non-fluorescent rare-earth ion, Ge, Er, and Tm. The non-fluorescent rare-earth ion may be La. Exemplary compositions concentrations are Er is from 15 ppm to 3000 ppm, Al is from 0.5 mol % to 12 mol %, La is less than or equal to 2 mol %, Tm is from 15 ppm to 10,000 ppm; and the Ge is less than or equal to 15 mol %. The core may further include F. An exemplary concentration of F is less than or equal to 6 anion mol %.

Abstract: The present invention relates to a transmission optical fiber. The transmission optical fiber including a core and a cladding made of SiO2 is characterized in that GeO2 and F are doped in SiO2 of the core and the cladding. Therefore, a high Raman gain coefficient could be obtained while a desired dispersion value and a non-linearity are maintained, by controlling the refractive index of the core and the cladding. Further, the pump power of the laser diode could be reduced and the cost of the laser diode could be lowered accordingly. In addition, the life of the laser diode is extended since the laser diode needs not to be operated at a high output.

Abstract: The present invention provides an optical fiber providing high photosensitivity in the absence of hydrogen loading as well as a low numerical aperture. One aspect of the present invention relates to an optical fiber including a core, the core comprising silica doped with at least about 6 mol % germania and at least about 0.9 wt % fluorine; and a cladding surrounding the core. The optical fiber of the present invention is suitable for the production of fiber Bragg gratings.

Abstract: An echelon diffraction grating which has excellent heat resistance and can be produced at a low cost and an optical waveguide which has high heat resistance, small absorption of a communication wavelength of a near infrared range, and satisfies reliability and a low loss at an optical communication range. The echelon diffraction grating comprises a substrate, and an organopolysiloxane film having a maximum thickness of 1 &mgr;m to 1 mm formed on the surface of the substrate and has a plurality of steps having a predetermined width of 1 to 500 &mgr;m and a predetermined height of 5 to 500 &mgr;m formed on the organopolysiloxane film, and the organopolysiloxane film contains dimethylsiloxane and phenyl(or substituted phenyl)siloxane as essential ingredients.

Abstract: A method of forming an alkali metal oxide-doped optical fiber by diffusing an alkali metal into a surface of a glass article is disclosed. The silica glass article may be in the form of a tube or a rod, or a collection of tubes or rods. The silica glass article containing the alkali metal, and impurities that may have been unintentionally diffused into the glass article, is etched to a depth sufficient to remove the impurities. The silica glass article may be further processed to form a complete optical fiber preform. The preform, when drawn into an optical fiber, exhibits a low attenuation.

Abstract: This invention relates to an optical fiber for amplification suitable for amplifying signals in the L-band, an optical fiber amplifier including the optical fiber, and an optical transmission system. The optical fiber amplifier according to the invention includes a silica-based optical fiber as an optical fiber for amplification, which has a core region doped with Er and Al. The optical fiber for amplification has an Er concentration of 1,500 wt.ppm or less, and has the characteristics at a wavelength of 1.53 &mgr;m of: an absorption loss of 10 dB/m or more but 25 dB/m or less; and an unsaturated absorption of 900 dB or less.

Abstract: The present invention provides an optoelectronic device, a method of manufacture therefore, or an optical communications system including the optoelectronic device. The optoelectronic device may include a substrate and a waveguide located within the substrate. Additionally, the waveguide may include a first portion having a width, depth, and refractive index, and a second portion having a different width, depth and refractive index.

Abstract: Disclosed is an amplifying optical fiber for amplifying optical signal transmitted therethrough by stimulated emission, the amplifying optical fiber comprising: an inner core disposed at a center of said optical fiber and containing MX, GaS3/2 and RE; an outer core surrounding said inner core and containing SiO2; and a cladding surrounding said outer core and containing SiO2, wherein said M contained in MX is one component selected from the group consisting of Na, K, Rb and Cs; said X contained in MX is one component selected from the group consisting of F, Cl, Br, and I; and said RE is one component selected from the group consisting of Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Ho, Dy, Er, Tm and Yb.

Abstract: A plastic optical fiber and a method for producing the same is disclosed. The plastic optical fiber is formed as a fiber of core-cladding structure. A protective layer or shield layer may be provided on the outer surface of the optical fiber of core-cladding structure for improving thermal resistance of the optical fiber and protecting the optical fiber from air and moisture. The plastic optical fiber uses fluorinated plastic, which contains a rare earth component as a core material, and a cladding material, which does not comprise a rare earth component but essentially consists of a polymer chain, which essentially consists of bonded —[CF2]n— monomers and has a refractive index lower than that of the core material. The optical fiber is produced by a melting-drawing technique.

Abstract: A thulium doped silicate glass composition which contains SiO2, Al2O3, and La2O3 emits visible and UV light when excited by infrared light. The glass composition may also contain GeO2 and Er2O3. When excited by infrared light of about 1060 nm, the glass emits visible light at fluorescent transitions of the Tm3+ ions with major broad features at 365, 455, 472, 651, and 791 nm.

Abstract: A dispersion control fiber and a method of manufacturing a large size preform. The dispersion control fiber includes a core composed of SiO2, GeO2, and P2O5, and a cladding composed of SiO2, GeO2, P2O5, and Freon. The P2O5 content is selected not to exceed 10% total weight of a compound composing the core. The method of manufacturing a large size perform for a dispersion control fiber by an MCVD process includes depositing SiO2, GeO2, P2O5, and Freon in an inner periphery of a deposition tube to form a cladding layer, and depositing SiO2, GeO2, and P2O5 on an inner periphery of the cladding layer to form a core layer.

Abstract: An optical fiber is composed of silica glass and comprises a center core region doped with F element, a ring core region doped with GeO2, and an inner cladding region doped with F element; wherein a buffer layer composed of undoped SiO2 or SiO2 doped with one or both of P and Cl or a concentration gradient region in which GeO2 concentration radially decreases toward the boundary is provided between the center core region and the ring core region.

Abstract: An apparatus and method for thermally tuning an optical amplifier comprises an optical waveguide doped with a fluorescent material, a thermal device for either heating or cooling the optical waveguide, and a pump light for exciting the fluorescent material. The apparatus shapes, shifts, and/or flattens the gain curves of the doped optical amplifier. Thulium doped fiber is cooled to shift the gain curve into the C-band. Erbium doped fiber is heated to flatten the gain curve in the C-band and is cooled to shift the gain curve above the L-band. The apparatus similarly shapes the gain curves of other fluorescent materials. The thermal device comprises three types of optical cooling devices. The apparatus is a component in communications systems, lasers, medical lasers and the like. The method comprises either heating or cooling optical waveguides doped with fluorescent materials to achieve the desired shaping, shifting, and flattening of the gain curves.

Abstract: Cd-free multicomponent glass to be used in particular as core glass (2) in glass fibers for optical twisters and tapers, the glass being of the lanthanide flint type and comprising the following main constituents (in mol %): B2O3 20-70 ZnO  1-15 Lanthanide oxide  1-23 ZrO2, and/or HfO2  1-10 As2O3 0.1-0.3.

Abstract: A two-dimensional photonic crystal slab apparatus having a waveguiding capability is provided. Noncircular holes are introduced to replace the circular holes in the two-dimensional lattice of the photonic crystal to provide waveguiding capability. High guiding efficiency is achieved over a wide frequency region within the photonic bandgap.

Abstract: An optical device includes a planar waveguide having a core region at least partially surrounded by a cladding, wherein the waveguide includes of a photosensitive germanium-doped silicon oxynitride (Ge:SiON) or germanium-doped silicon nitride (Ge:SiN). An optical device is formed by providing a photosensitive layer comprised of Ge:SiON or Ge:SiN and selectively irradiating the photosensitive layer at a wavelength of light to which the photosensitive material is sensitive, such that an optical feature having a refractive index different than that of the non-irradiated photosensitive layer is formed.

Abstract: A planar lightwave circuit comprises a waveguide that is thermally-compensating. The waveguide comprises a cladding and a core that comprises two regions running lengthwise through the core. One region has a negative thermo-optic coefficient; the other region has a positive thermo-optic coefficient.

Abstract: An active photonic crystal device for controlling an optical signal is disclosed. The device includes a planar photonic crystal with a defect waveguide bounded on the top and bottom by an upper cladding region and a lower cladding region. An optical signal propagating in the defect waveguide is confined in the plane of the photonic crystal by the photonic bandgap, and in the direction normal to the photonic crystal by the upper clad region and the lower clad region. The propagation of the optical signal in the defect waveguide is controlled by varying the optical properties at least one of the upper clad region or the lower clad region. The variation of the optical properties of the controllable regions may be achieved using a thermo-optic effect, an electro-optic effect, a stress-optic effect, or a mechano-optic effect, or by moving a material into or out of the controllable region.

Abstract: A semiconductor waveguide is disclosed which includes a substrate coated with a cladding. A core is embedded in the cladding. The core includes a plurality of discreet stacked layers of core material surrounded by cladding material. The cladding and core layers each include silica and silicon nitride with the core layers having a higher nitrogen content than the cladding material. The core is fabricated by carefully manipulating the process parameters of a PECVD process.

Abstract: A modified silica glass composition for providing a reduction in the multiphonon quenching for a rare-earth dopant comprising: SiO2 in a host material; a rare-earth dopant; a first SiO2 modifier; and a second SiO2 modifier; such that said first modifier and said second modifier reduce multiphonon quenching of the rare-earth dopant contained therein.

Abstract: A tellurite glass material has a composition of Li2O:TiO2:TeO2, and contains a dopant comprising ions of a rare earth metal. The rare earth ions can be thulium ions, Tm3+, to provide a material offering optical gain at 1470 nm. The properties of the glass make it suitable for the fabrication of high quality optical fibers and planar waveguides, which can in turn be used in optical amplifiers and oscillators. Co-doping the glass with acceptor ions such as holmium ions, Ho3+, improves the population inversion in the rare earth ions and hence enhances the gain.

Abstract: An optical waveguide in which a groove is formed on the top surface of a substrate used as a lower clad and a core is formed in the groove, characterized in that the core is formed in such a way that the top face of the core within the groove is at a lower level than the top face of the substrate, and an upper clad may also be provided on the core, and the core is preferably formed from an organic-inorganic hybrid material.

Abstract: A glass fiber comprising core glass and clad glass, wherein the core glass consists essentially of from 25 to 70 mol % of Bi2O3, from 5 to 74.89 mol % of B2O3+SiO2, from 0.1 to 30 mol % of Al2O3+Ga2O3, and from 0 to 10 mol % of CeO2.

Abstract: An optical waveguide is produced by forming on a substrate a waveguide layer and/or a clad layer containing, as their main ingredient, polyimide with a fluorine substitution rate of 30% or higher (thus as a fluorinated polyimide layer), with a primer layer laid in between that contains, as its main ingredient, polyimide with a fluorine substitution rate of 10% or lower (including 0%). This improves adherence of the fluorinated polyimide layer to the substrate and prevents the fluorinated polyimide layer from peeling off the substrate. For more effective prevention of such peeling-off and of warping of the substrate, the primer layer is preferably formed to have a thickness of 0.1 to 20 &mgr;m. The primer layer may contain a coupling agent.

Abstract: A long period grating (8) by which an excitation light propagated through the 2nd core (4) of a double-core type optical fiber composed of the 2nd core (4) formed on the outer circumference of the 1st core (2) is guided into the 1st core (2) is formed on the 1st core (2) to improve an excitation efficiency.

Abstract: The present invention relates to an optical fiber having improved hydrogen-resistance properties. The optical fiber includes a high concentration germanium layer and a low concentration germanium layer. The high concentration germanium layer is disposed at a central position of the optical fiber and contains germanium oxide in a concentration of 0.1% by weight or more, relative to the total weight of the high concentration germanium layer. The low concentration germanium layer is disposed around the high concentration germanium layer and contains germanium oxide in a concentration of less than 0.1% by weight, relative to the total weight of the low concentration germanium layer. The ratio of optical power leaking from the high concentration germanium layer to the low concentration germanium layer in an employed wavelength band is 0.4% or less, relative to the total optical power propagating through the optical fiber.

Abstract: Optical waveguides having a waveguide channel of photosensitive silica glass with a modified refractive index optically written therein, wherein the photosensitive glass comprises oxides of silicon, tin and at least one Group I element, where such optical waveguide devices include optical fiber gratings, optical fiber dispersion compensators, optical fiber sensors, optical fiber lasers, and planar waveguide devices.

Abstract: A dispersive optical fiber having variable core-cladding refractive index differences depending on wavelength is provided. The dispersive optical fiber includes a core made of silica doped with a first dispersive material, and a cladding made of silica doped with a second dispersive material, wherein the refractive indices of the first and the second dispersive materials cross each other at a predetermined cross wavelength. The first and second dispersive materials include boron and fluorine. The dispersive optical fiber is attained by doping each dispersive material into the core and the cladding, respectively, thereby minimizing transmission loss, and is capable of being coupled to general optical fibers.

Abstract: The invention provides a monomode optical fiber and a monomode preform (2) having a mother preform (22) housed in an outer sleeve tube (20). It is characterized in that it also includes an intermediate tube (21) between the mother preform (22) and the outer tube (20), the intermediate tube (21) possessing viscosity at fiber-drawing temperature which is less than the viscosity(ies) at fiber-drawing temperature of the mother preform (22) and of the outer tube (20). The invention also provides a method of manufacturing a monomode optical fiber. The fiber has a core that is better centered and less deformed than in the prior art. An application of the invention lies in making an optical amplifier.

Abstract: A thulium doped silica based glass capable of supporting lasing activity including Tm3+ as a lasing species disposed in a host composition, including oxides of germanium, silicon and tantalum. The preferred concentration of silicon in the host composition being between 15-25 weight percent. The preferred concentration of germanium in the host composition being between 0.1-1 weight percent. The preferred concentration of tantalum in the host composition is greater than 15 weight percent. The preferred concentration of thulium ions being in the range of 500-1000 parts per million by weight.

Abstract: A solid substrate comprising a first major surface, a second major surface juxtaposed from and parallel or substantially parallel to the first major surface, wherein the substrate has a plurality of surface relief structures, located on the substrate between the first and second major surfaces, and extending over the substrate; wherein the solid substrate comprises a host matrix, and at least one nanoparticle within the host matrix.

Abstract: A lower clad, cores, and an upper clad are formed by a chemical vapor deposition method (CVD method). At least one of the additional amount of oxygen, the additional amount of nitrogen, and the additional amount of silicon of a silicon oxynitride film is adjusted so that the cores have a desired higher refractive index than those of the clads. Further, end point detectors are formed which become etching stoppers of dry etching in pattern forming the cores.

Abstract: A method of making a photonic device having at least two layers formed over a substrate, preferably by plasma enhanced chemical vapor deposition, involves depositing a thin spin-on glass (SOG) interlayer between at least one adjacent pair of layers to improve the roughness characteristics.

Abstract: The present invention concerns an optical guide (100) comprising an amplifier medium including:

Abstract: A glass planar waveguide structure, typically on a glass wafer or chip, has a core region, a contiguous narrow cladding region encompassing the core region, and an outer region practically extending over the rest of the wafer. The core region and the outer region are implanted with outside ions by ion diffusion, whereby the refractive index of the core and of the outer region are similar. The outer region forms an artificial waveguide to enhance the uniformity of physical properties of the wafer, e.g. stress, and reduce birefringence of the core.

Abstract: Methods of fabricating solid state optical waveguide structures comprising a doped silicon dioxide core layer sandwiched between lower and upper doped silicon dioxide cladding layers on a silicon substrate. The core and upper cladding layers are deposited using a plasma enhanced CVD process. The core layer is patterned to define one or more waveguide cores. The lower cladding layer is preferably also deposited using a plasma enhanced CVD process but alternatively may be formed by thermal oxidation.

Abstract: The invention relates to an optical amplifier, in particular for optical fiber telecommunication lines (1), operating with a transmission signal in a predetermined wavelength range, which amplifier comprises a fluorescent active optical fiber (6) doped with erbium, having two cores (11 and 12, 101 and 102), one (11, 101) of which is connected to a fiber (4) in which a transmission signal to be amplified and a luminous pumping energy are multiplexed, and to an outgoing fiber adapted to transmit the amplified signal, whereas the second core (12, 102) is optically coupled to the first core and is capable of absorbing the spontaneous erbium emission which would constitute a noise source, allowing a signal to be amplified in a wavelength range substantially corresponding to the tolerance range of the commercially available signal laser emitters.