Abstract: An optical waveguide includes a sapphire body having thereon a cladding containing spinel.

Abstract: Disclosed herein is an optical fiber including a core doped with first metal ions; and a cladding formed so as to surround the core and doped with second metal ions selected so that the absorption coefficient in a transition wavelength band of first transition of the first metal ions is greater than the absorption coefficient in a transition wavelength band of second transition of the first metal ions. The amplification of light due to the first transition is suppressed, and at least the amplification or oscillation of light due to the second transition is effected. Also disclosed are an optical amplification/oscillation device, a laser light generating device, and a laser display unit, and a color laser display unit each employing the optical fiber.

Abstract: A coated optical fiber can have a primary coating and a secondary coating, where the primary coating can have good microbending resistance and is obtained by curing a composition having a high cure speed. In one example, a coated optical fiber can include as optical fiber, a primary coating and a secondary coating. The optical fiber can have an attenuation increase of less than 0.650 dB/km at 1550 nm, with the primary coating having a modulus retention ratio of at least 0.5, a glass transition temperature of ?35° C., and where the primary coating is obtained by curing a primary coating composition having a cure dose to attain 95% of the maximum attainable modulus of less than 0.65 J/cm2.

Abstract: An optical fiber suitable to support single mode optical transmission at longer wavelengths (e.g., 1550 nm) is formed to comprise a pure silica core region and a “down doped” cladding layer. The core region is defined as having a diameter d and the cladding layer is defined has having an outer diameter D. In accordance with the present invention, single mode propagation will be supported when D/d>8.5, and is preferably in the range of 9–10.

Abstract: The invention pertains to optical fiber transmission networks, and is particularly relevant to transmission of high volume of data and voice traffic among different locations. In particular, the improvement teaches improvements to an optical transport system to allow for efficient and flexible network evolution.

Abstract: The present invention is a thulium doped silicate glass having an excellent fluorescent emission in the 1.4 ?m band, and the usage thereof. The silicate glass of this invention includes: 65˜95 mol % SiO2; 0.5˜30 mol % bivalent metal oxide consisting of one or more material selected from ZnO, BaO, SrO and PbO; and 1˜15 mol % of SnO2 or TiO2, wherein 3˜30 mol % oxygen of the glass composition are replaced with fluorine, and 0.01˜1 mol % of thulium ions are doped, and the fluorescence lifetime of the 3H4 level of the Tm3+ is more than 50 ?s. The silicate glass can be easily formed into a waveguide, such as optical fiber, and it has an excellent ability to splice with the optical fiber for transmission. They have excellent chemical durability and the characteristic of 1.4 ?m band fluorescent emission by suppressing the non-radiative transition through multi-phonon relaxation. Thus they have long fluorescence lifetime of the 3H4 of Tm3+.

Abstract: An optical waveguide is provided. The optical waveguide includes a polymer substrate and a lower cladding disposed on the substrate. The lower cladding is a first perhalogenated polymer. The optical waveguide also includes a core disposed on at least a portion of the lower cladding. A method of manufacturing the optical waveguide is also provided.

Abstract: Cores are embedded in a cladding, each core constituting a continuous optical path in which a first core end surface is exposed at a first end surface, and a second core end surface is exposed at a second end surface. Each of the continuous optical paths extends from the first core end surface to a mirror surface, is changed in direction at the minor surface, and then extends to the second core end surface. The first core end surfaces and the second core end surfaces are respectively arranged two-dimensionally at the first end surface and the second end surface.

Abstract: An optical module of the present invention includes a first substrate 1, a second substrate 2, a PD 3, a LD 4, and an optical fiber 5. The first substrate 1 has a first optical waveguide core 1c formed therein. The second substrate 2 has a second optical waveguide core 2c formed therein. The first optical waveguide core 1c and the second optical waveguide core 2c form an optical connecting portion where the first substrate 1 and the second substrate 2 are bonded to each other. The LD 4 is capable of transmitting an optical signal via the second optical waveguide core 2c and the optical fiber 5. The PD 3 is capable of receiving an optical signal which enters the second optical waveguide core 2c from the optical fiber 5, and propagates through the first optical waveguide core 1c via the optical connecting portion formed between the first optical waveguide core 1c and the second optical waveguide core 2c.

Abstract: A cycloolefin in copolymeric (COC) optical communication device. The COC optical communication device includes a core section of functional metallocene cycloolefin copolymer (f-mCOC) having a refractive index n1 for light transmission, and a cladding layer of metallocene cycloolefin copolymer (mCOC), having a refractive index n2 smaller than n1, surrounding the core section and forming a waveguide structure together with the core section. Due to the fact that the various components of the optical communication device are comprised of essentially the same materials, signal transmission loss between heterogeneous interfaces is prevented, and provides excellent optical properties and superior processability.

Abstract: A method for manufacturing an article capable of constraining a propagating wave is disclosed. The method includes contacting a crystalline substrate with a source of deuterium ions to create a region in the crystalline substrate having a crystal structure that includes deuterium ions. The region is capable of constraining a propagating wave to the region.

Abstract: Disclosed herein is an optical fiber including a core doped with first metal ions; and a cladding formed so as to surround the core and doped with second metal ions selected so that the absorption coefficient in a transition wavelength band of first transition of the first metal ions is greater than the absorption coefficient in a transition wavelength band of second transition of the first metal ions. The amplification of light due to the first transition is suppressed, and at least the amplification or oscillation of light due to the second transition is effected. Also disclosed are an optical amplification/oscillation device, a laser light generating device, and a laser display unit, and a color laser display unit each employing the optical fiber.

Abstract: The present invention provides an optical polyimide precursor for use in making a polyimide. The precursor is defined by the following formula: wherein X is Cl, Br, oxo-halide, or fully halogenated alkyl, and A is a divalent aromatic or halogenated aromatic moiety. The present invention provides a method of preparing a diamine compound for use as an optical polyimide precursor. The method includes the steps of dissolving 2-chloro-5-nitrobenzotrifluoride and a diol in N,N-dimethylacetamide to form a solution, adding potassium carbonate, tert-butylammonium chloride and copper powder to said solution and heating the resulting mixture, removing the copper, precipitating and recrystallizing a dinitro-compound resulting from heating the mixture, and dissolving the dinitro-compound and reducing the dinitro-compound to yield a diamine compound.

Abstract: The present invention provides an optical fiber, an optical fiber cable and a radiation detecting system at a low cost. Further, the radiation detecting system is provided which can adequately monitor the radiation leak without delay. The optical fiber cable comprises: an optical fiber including; a core 12 having lightwave guide property and extending along one direction; a clad layer 14 covering over a peripheral surface of the core 12; and a scintillator material dispersed in the clad layer 14 and emitting light when radiation is applied, a radiation-shielding layer 24 covering substantially over a periphery of the optical fiber10, and a gap 26 located in at least one part of the radiation-shielding layer 24.

Abstract: An optical component and a method of making the same are provided. In one embodiment, the optical component is a low-OH optical fiber that includes a core and a cladding. The optical component is treated by immersion in a hydrogen gas atmosphere at a predetermined pressure, at a predetermined temperature and for a predetermined time period such that intrinsic and impurity defects of the optical component are destroyed. The method of making the optical component includes providing a preform having a content of OH-groups in the amount of about 0.1 to about 10.0 ppm and a content of chlorine in the amount of 0 to about 1000 ppm and drawing the preform to elongate it to form an optical component from the preform. The optical component is immersed in a hydrogen gas atmosphere at a predetermined pressure, at a predetermined temperature and for a predetermined time period that is sufficient to destroy intrinsic and impurity defects of the optical component.

Abstract: An optical fiber having an elevated threshold for stimulated Brillouin scattering is provided. The optical fiber includes a core and a cladding surrounding the core with both the core and the cladding designed to guide optical waves through the core while anti-guiding acoustic waves. Moreover, the optical fiber includes other features to alter the mode profile of the acoustic waves and/or to further promote their lateral radiation. For example, the optical fiber can include an irregular coating to alter the mode profile of the acoustic waves. In another example, the optical fiber can include a quarter wave layer surrounding the cladding to promote the lateral radiation of the acoustic waves. In order to further alter the mode profile of the acoustic waves, the cladding can also have a lateral thickness that varies irregularly in a lengthwise direction.

Abstract: The present invention relates to a process for preparing an optical waveguide component from acrylate/titanium alkoxide composite material, which is characterized by using an acid-free sol-gel process to prepare a precursor solution of acrylate/titanium alkoxide composite film, then coating the precursor solution on a silicon wafer then drying, and producing the optical waveguide component having channels by using a lithography process. The present invention also relates to an optical waveguide component of acrylate/titanium alkoxide composite material, the material has excellent transparency and its refractive index varies with the amount of titanium alkoxide contained therein. When an optical waveguide component is prepared from the composite the reduction of near-infrared ray is less than 0.7 dB/cm and therefore the waveguide component is advantageous for use as an optical communication element.

Abstract: An optical fiber for use in making components of an optical communication system has cladding and core materials the constituents of which cause a component made from the fiber to have a rate of change with respect to temperature of a response to a signal which passes through zero at a temperature Tm which is at or near a selected temperature, or falls within a selected temperature range; and the value of Tm of a fiber can be controllably changed by changing the concentration of B2O3 in the fiber core material.

Abstract: A magneto-optical device includes a waveguide structure that has at least one cladding region and core region. The cladding region and core region comprise semiconductor alloy materials. Either the at least one cladding region or the core region is doped with ferromagnetic materials so as to increase the magneto-optical activity of the device.

Abstract: An optical waveguide includes a sapphire body having thereon a cladding containing spinel.

Abstract: In a laser device and a light signal amplifying device with an optical fiber containing a laser activating substance in the inside for emitting a light beam from the end part in the case the laser activating substance is excited, fixed in a dense state at least partially by an optical medium, a polysilsesquioxane including a repeating unit represented by a general formula RSiO1.5 (wherein R represents an alkyl group, a hydroxyl group, a phenyl group, a vinyl group, a 2-chloroethyl group, a 2-bromoethyl group, a hydrogen, a heavy hydrogen, a fluorine, or an oxygen. However, one having R entirely as an oxygen is excluded. Moreover, R may be different per each repeating unit.) is used as the optical medium.

Abstract: A glass article comprising a glass substrate and a diamond-like film deposited on the substrate is disclosed. The glass article is desirably responsive to actinic radiation, such as being capable of demonstrating a change in refractive index upon exposure to actinic radiation. The film permits passage of the actinic radiation. through the film and into the substrate. In specific implementations, the film comprises at least about 30 atomic percent carbon, from about 0 to about 50 atomic percent silicon, and from about 0 to about 50 atomic percent oxygen on a hydrogen-free basis.

Abstract: An optical waveguide capable of having various characteristics and a method of manufacture thereof as well as a method of manufacturing a crystal film are provided. An optical functional material KTaxNb1-xO3 is used as an optical waveguide. The input optical signal is transmitted to the KTaxNb1-xO3 film. The KTaxNb1-xO3 film undergoes changes in optical property when an external voltage signal is applied to the electrode. Therefore, as it passes through the KTaxNb1-xO3 film, the input optical signal is modulated by the characteristic change. The modulated optical signal is taken out as an output optical signal.

Abstract: The invention provides polymeric optical materials that can be cured in air and have low optical loss in both the C-band and the L-band of the telecommunications spectrum. The polymeric materials are made by the free radical polymerization of an at least difunctional thiol compound with an at least difunctional ethylenically unsaturated compound wherein at least one of the thiol compound and the ethylenically unsaturated compound is at least partially halogenated. The compositions of this invention may be used to fabricate planar optical waveguides with low loss and low birefringence.

Abstract: Materials, both glass and glass-ceramic, that exhibit UV-induced changes in light transmission and electrical conductivity behavior. The materials consist essentially, in mole %, of 20-40% SiO2, 10-20% AlO1.5, 35-55% SiO2+AlO1.5, at least 30% CdF2, 0-20% PbF2, and/or ZnF2, 0-15% rare earth metal fluoride, and 45-65% total metal fluorides.

Abstract: The present invention relates to an optical fiber having a structure which allows further improvements to be made both in terms of lower reflectance and narrower bandwidth, and to a fiber grating type filter including the optical fiber. The optical fiber applied to the fiber grating type filter comprises a core region extending along a predetermined axis, and a cladding region provided on an outer periphery of the core region. The core region does not contain any photosensitive dopant which contributes to predetermined wavelength light photosensitivity as a glass property, but a part of the cladding region contain such a photosensitive dopant. By means of this composition, it is possible to form a grating, which has a grating plane slanted by a predetermined angle with respect to the optical axis, in a part of the cladding region surrounding the core region.

Abstract: Germanium-silicon oxide, germanium-silicon oxynitride and silica-germania-titania materials and oxynitride materials suitable for fabricating optical waveguides for liquid crystal based cross-connect optical switching devices have a refractive index of from about 1.48 to about 1.52 at 1550 nm, and a coefficient of thermal expansion at room temperature of from about 3×10−6° C.−1 to about 4.4×10−6° C.−1. The compositions are adjusted so that the refractive index of the germanium-silicon oxide, germanium-silicon oxynitride or silica-germania-titania material is closely matched to the refractive index of a typical liquid crystal material whereby improved optical performance of a liquid crystal based cross-connect optical switching device is achieved.

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: 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, an optical fiber cable and a radiation detecting system at a low cost. Further, the radiation detecting system is provided which can adequately monitor the radiation leak without delay. The optical fiber cable comprises: an optical fiber including; a core 12 having lightwave guide property and extending along one direction; a clad layer 14 covering over a peripheral surface of the core 12; and a scintillator material dispersed in the clad layer 14 and emitting light when radiation is applied, a radiation-shielding layer 24 covering substantially over a periphery of the optical fiber 10, and a gap 26 located in at least one part of the radiation-shielding layer 24.

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: 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: The present invention relates to a multimode fibre having a refractive index profile, wherein the area surrounding the centre of the fibre has a refractive index profile such that the responses of a DMD (Differential Mode Delay) measurement carried out on a fibre having a length of at least 300 m are obtained without any pulse splitting occurring in the centre of the fibre.

Abstract: The present invention relates to a composition for coating optical fibers that includes a UV curable coating composition. The composition includes at least one component having at least one heterocyclic moiety capable of undergoing ring opening polymerization. The composition may also include at least one acrylate functional end group. The acrylate functional group may be on the same component as the heterocyclic moiety or on a second component. The cured composition has a Young's Modulus of at least about 100 MPa.

Abstract: An optical fiber having an elevated threshold for stimulated Brillouin scattering is provided. The optical fiber includes a core and a cladding surrounding the core with both the core and the cladding designed to guide optical waves through the core while anti-guiding acoustic waves. Moreover, the optical fiber includes other features to alter the mode profile of the acoustic waves and/or to further promote their lateral radiation. For example, the optical fiber can include an irregular coating to alter the mode profile of the acoustic waves. In another example, the optical fiber can include a quarter wave layer surrounding the cladding to promote the lateral radiation of the acoustic waves. In order to further alter the mode profile of the acoustic waves, the cladding can also have a lateral thickness that varies irregularly in a lengthwise direction.

Abstract: There is disclosed a method for producing a base material for optical fiber having a deformed first clad consisting of at least a core, a first clad and a second clad, comprising a step of deforming a shape of a section of the first clad so that it may have at least one linear part when the first clad is formed around the core, a step of depositing porous glass fine particles as the second clad made of the same material as that of the first clad on a glass rod having the deformed first clad to form a porous glass base material, and a step of forming the second clad having a round section by vitrifying it. There can be provided a method for producing a base material for optical fiber wherein a lot of breakages or cracks on the surface of the base material can be prevented in a step of depositing porous glass fine particles for the second clad on the first clad, and base material for optical fiber having no defects, and an optical fiber having an efficient effect of being excited with excitation light.

Abstract: The present invention provides an optical fiber, an optical fiber cable and a radiation detecting system at a low cost. Further, the radiation detecting system is provided which can adequately monitor the radiation leak without delay. The optical fiber cable comprises: an optical fiber including; a core 12 having lightwave guide property and extending along one direction; a clad layer 14 covering over a peripheral surface of the core 12; and a scintillator material dispersed in the clad layer 14 and emitting light when radiation is applied, a radiation-shielding layer 24 covering substantially over a periphery of the optical fiber10, and a gap 26 located in at least one part of the radiation-shielding layer 24.

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 fiber amplifier in which the active core is surrounded by a cladding and coupling of radiation between a core mode and cladding modes is suppressed to minimize cladding mode losses in a short wavelength range. An index profile is established in the active core and in the cladding such that the core exhibits a loss above a cutoff wavelength &lgr;c and positive gains in the short wavelength range below the cutoff wavelength &lgr;c. Suppression of cladding mode losses is achieved by an arrangement for suppressing the coupling of radiation in the short wavelength range between a core mode supported the active core and a cladding mode supported by the cladding. The arrangement for suppressing can include an absorbing material or a scattering material distributed in the cladding. The arrangement for suppressing can include a non-phase-matched length section of the fiber amplifier in which the core mode and the cladding modes are not phase matched.

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 apparatus including a cladding-pumped optical fiber that includes a core that includes an active material, a multimode inner cladding disposed about the core, and a second cladding disposed about the multimode inner cladding. The cladding-pumped optical fiber can include, disposed about the inner cladding layer, an asymmetrical layer, a layer that includes granular matter, a compressive layer, or a hard layer. External provision can be included for applying stress to the cladding-pumped optical fiber.

Abstract: A continuously variable fiber-optic delay line is created from a deformable polymeric fiber in which lighter density elements, e.g. hydrogen, boron, carbon or oxygen, are diffused through the outer surface of the fiber. The diffusion of the lighter elements creates a non-light transmissive cladding that is of a refractive index that increases from the surface of the fiber towards its axis. The cladding longitudinally surrounds a light transmissive core and has a maximum refractive index that is less than any refractive index of the core. A single-mode, graded-index polymeric fiber is thereby created. By applying a reversible and controllable pressure to the exterior of the deformable fiber, the refractive index of the fiber can be changed accordingly. This change in refractive index permits one to continuously vary the time delay of a signal transmitted through a fixed length of the fiber.

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: To overcome problems of fabricating conventional core-clad optical fibre from non-silica based (compound) glass, it is proposed to fabricate non-silica based (compound) glass optical fibre as holey fibre i.e. one contining Longitudinal holes in the cladding. This removes the conventional problems associated with mismatch of the physical properties of the core and clad compound glasses, since a holey fibre can be made of a single glass composition. With a holey fibre, it is not necessary to have different glasses for the core and cladding, since the necessary refractive index modulation between core and cladding is provided by the microstructure of the clad, i.e. its holes, rather than by a difference in materials properties between the clad and core glasses. Specifically, the conventional thermal mismatch problems between core and clad are circumvented.

Abstract: A dispersion compensating fiber is described having a core and cladding as well as methods for making such fiber. The cladding has a first cladding region surrounding the core, a second cladding region surrounding the first cladding region, and a third cladding region surrounding the second cladding region. The core, and the first, second, and third cladding regions are doped to create a refraction index profile characteristic of dispersion compensating fiber. The core is doped with germanium, the first cladding region is doped with fluorine, and the second cladding region is doped with germanium and fluorine. A portion of the cladding is doped with phosphorus, thereby resulting in splice loss reduction.

Abstract: A UV light-curable composition comprises: (a) a first component, said first component being UV light-polymerizable polymer having a first index of refraction; and (b) a second component, the second component being UV light-polymerizable monomer having a second index of refraction, the second index of refraction being higher than said first index of refraction; wherein the first component polymerizes slower upon exposure to UV radiation than the second component.

Abstract: The present invention relates to an optical fiber having a sufficient strength, in which not only a core region but also a cladding region contains GeO2, and an optical component including the same. The optical fiber has an outer diameter D; and comprises a core region, a first cladding region surrounding the core region, and a second cladding region surrounding the first cladding region. The core region is a glass region mainly composed of a silica glass material with a GeO2 content of 1 wt % or more. The first cladding region is a glass region, mainly composed of a silica glass material with a GeO2 content of 1 wt % or more, having an outer diameter of 0.80D or more but 0.98D or less. The second cladding region is a glass region mainly composed of a silica glass material with a GeO2 content of less than 0.2 wt %.

Abstract: In a covering outside its light-guiding portion, an optical fiber includes at least one crystalline intermetallic compound made up of at least two metals, the compound having a plateau pressure during hydride formation that is less than equal to 5×10−2 atm (where 1 atm=1.013×105 Pa) as measured at 30° C. by a PCT method, the compound being of the form ABxMy where A is constituted by at least one element from columns IIa, IIIb, or IVb of the periodic classification of the elements (CAS version), B is constituted by at least one element from columns Vb, VIII, or IIIa of said classification, and M contains at least one element from columns VIb, VIIb, Ib, or IIb of said classification, where: 0≦x≦10, 0≦y≦3 if A contains elements from column IIa only, and 0.2≦y≦3 if A contains at least one element from columns IIIb or IVb. The optical fiber cable is characterized in that it includes such a crystalline intermetallic compound.

Abstract: A method of controlling birefringence in a rib waveguide structure manufactured in silicon is describes. The rib waveguide structure comprises an elongated rib element having an upper face and two side faces. According to the method, a blanket layer of silicon nitride is formed to a predetermined thickness over the rib waveguide structure directly abutting the upper face and side faces. The thickness of the blanket layer is selected to control birefringence. A silicon rib waveguide structure incorporating such a layer and a evanescent coupler structure are also described.