586 results about "Relative refractive index" patented technology

A bending-resistant large core diameter high numerical aperture multimode fiber includes a core and a cladding surrounding the core. The core has a radius R1 in a range of 28 to 50 microns, a refractive index profile of a parabola shape with α being in a range of 1.9 to 2.2, and a maximum relative refractive index difference Δ1% max being in a range of 1.9% to 2.5%. The cladding includes an inner cladding and/or a trench cladding, and an outer cladding disposed from the inner to the outer in sequence. The radius R2 of the inner cladding is in a range of 28 to 55 microns, and the relative refractive index difference Δ2% is −0.1% to 0.1%. The radius R3 of the trench cladding is in a range of 28 to 60 microns, and the relative refractive index difference Δ3% is in a range of −0.15% to −0.8%.

An optical waveguide includes a substrate in the shape of a flat plate; lower clad that is disposed on the substrate; and a core that is disposed on the lower clad and transmits light. The optical waveguide includes a first optical waveguide and a second optical waveguide. The first optical waveguide includes a first core on the lower clad, and is disposed so as to extend along a direction in which the light travels to a first position. The second optical waveguide includes a second core on the lower clad, is disposed so as to extend along a direction in which the light travels to a second position, and has a lower relative refractive index difference than the first optical waveguide. The first optical waveguide and the second optical waveguide form, between the first position and the second position, a layer structure where the first core and the second core are disposed such that the first core is positioned a predetermined distance away from the second core in a direction perpendicular to the substrate. At least either the first optical waveguide or the second optical waveguide includes a mode coupling section and a mode conversion section. The mode coupling section includes a directional coupler to conduct the mode coupling of the first core and the second core between the first position and the second position. The mode conversion section is connected to the mode coupling section, and has a tapered core structure to adjust the mode diameter of the first core to the mode diameter of the second core.

An optical fiber includes: a core at a center; a first cladding layer; a second cladding layer; and a third cladding layer. A maximum refractive index of the core is greater than any of maximum refractive indices of the first cladding layer, the second cladding layer, and the third cladding layer, and the maximum refractive index of the second cladding layer is smaller than any of the maximum refractive indices of the first and the third cladding layer. Additionally, a ratio of a₂/a₁ is not less than about 2.5 and not more than about 4.5, where a1 represents the radius of the core, and a2 represents the radius of an outer periphery of the first cladding layer, and a relative refractive index difference of the core with respect to a maximum refractive index of the third cladding layer is not less than 0.20% and not more than 0.70%.

The invention relates to a low-attenuation single mode optical fiber used in an optical fiber communication system. The single mode optical fiber comprises a core layer and a wrapping layer. The single mode optical fiber is characterized in that the refractive index distribution n (r) of the core layer and the g-type refractive index distribution of the core layer meet the formula: n (r)=n0*[1-2*delta 1*(r/R1)*g]*1/2 (r<=R1), the delta 1 of the core layer ranges from -0.05% to +0.05%, g ranges from 10 to 30, and the radius R1 of the core layer ranges from 4.0 microns to 5.0 microns; the wrapping layer sequentially comprises an inner wrapping layer, a middle wrapping layer and an outer wrapping layer from inner to outer, the delta 2 of the inner wrapping layer ranges from -0.3% to -0.45%, the radius R2 ranges from 20 microns to 30 microns, and the delta 3 of the middle wrapping layer is larger than delta 2, the numerical relationship between the relative refraction difference and the radius of the middle wrapping layer and the relative refraction difference and the radius of the inner wrapping layer is V=(R3-R2)*(delta 3-delta 2), and V ranges from 0.5*10-2-micron% to 7*10-2-micron%. The attenuation coefficient, at the 1550-nanometer position, of the optical fiber is smaller than or equal to 0.180dB/km. The low-attenuation single mode optical fiber is low in optical fiber loss, good in manufacturing technology, low in cost and suitable for scale production.

The invention relates to a low-attenuation bend-insensitive single-mode fiber, which is used in a fiber communication system and comprises a core layer and three claddings. The low-attenuation bend-insensitive single-mode fiber is characterized in that the relative refractive index difference delta1 of the core layer ranges from 0.1% to 0.30%, the radius R1 of the core layer ranges from 3.5 micrometers to 4.5 micrometers, the three claddings are arranged on the outside of the core layer, the first cladding is an inner cladding tightly encircling the core layer, the relative refractive index difference delta2 of the inner cladding ranges from -0.1% to 0.1%, the radius R2 of the inner cladding ranges from 8 micrometers to 10 micrometers, the second cladding is a depressed cladding tightly encircling the inner cladding, the relative refractive index difference delta3 of the depressed cladding ranges from -0.4% to -0.1%, the delta3 is smaller than the delta2, the radius R3 of the depressed cladding ranges from 12 micrometers to 20 micrometers, the third cladding is an outer cladding tightly encircling all sub-claddings of the depressed cladding, and the relative refractive index difference delta4 of the outer cladding ranges from -0.2% to 0.1%. On the basis of comprehensive compatibility to existing G.652 standards, the low-attenuation bend-insensitive single-mode fiber has an attenuation performance far superior to that of a conventional G.652.D fiber, the microscopic bending requirement of G.657.A1 standards can be met, and application of a dense wavelength division multiplexing system is facilitated.

An optical fiber includes a first core having a relative refractive index difference of larger than 0.36%, and a cladding. The optical fiber has fiber cut-off wavelength λc of more than 1350 nm, cable cut-off wavelength λcc of less than 1285 nm, bending loss at a wavelength of 1625 nm of not more than 10 dB/km when wound at a diameter of 20 mm, transmission loss at a wavelength range of 1285 to 1625 nm of not more than 0.40 dB/km, transmission loss at a wavelength of 1383 nm less than transmission loss at a wavelength of 1310 nm, and difference in transmission loss at a wavelength of 1383 nm of not more than 0.04 dB/km before and after exposure to hydrogen. The lower bending loss of the optical fiber provides an optical fiber cable for use in a WDM transmission in wavelength range of 1285 to 1625 nm.

An optical fiber according to an embodiment of the present invention comprises: a glass core extending from a centerline to a radius R₁ wherein R₁ is greater than about 5 μm; a glass cladding surrounding and in contact with the core, the cladding comprising: (i) a first annular region extending from the radius R₁ to a radius R₂, the first annular region comprising a radial width, W₂=R₂−R₁, (ii) a second annular region extending from the radius R₂ to a radius R₃, and comprising a radial width, W₃=R₃−R₂, and (iii) a third annular region surrounding the second annular region and extending from the radius R₃ to an outermost glass radius R₄; wherein the core comprises a maximum relative refractive index, Δ_1MAX, relative to the third annular region, and wherein Δ_1MAX is greater than about 0.1% and less than about 0.3%; the first annular region has a refractive index delta Δ₂(r) is less than about 0.025%; wherein the second annular region comprises a minimum relative refractive index, Δ_3MIN, relative to the third annular region;

wherein Δ_1MAX>Δ_2MAX>Δ_3MIN, and Δ_2MIN>Δ_3MIN<0; and

wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 95 μm² and bend loss of ≦0.5 dB/turn on a 20 mm diameter mandrel.

An optical waveguide fiber comprising:

(i) a Ge free core having an effective area of 90 μm² to 160 μm², at a 1550 nm wavelength, and α value 12≦α≦25, said core comprising:

(a) a central core region extending radially outwardly from a centerline to a radius r₀≦2 μm, and having a relative refractive index percent profile Δ₀(r) wherein −0.1% ≦Δ₀(r) ≦0.1%, and wherein the central core region has a maximum relative refractive index, Δ_0MAX,

(b) a first annular core region surrounding and directly adjacent to the central core region and extending to an outer radius r₁, wherein 4.8 μm ≦r₁≦10 μm, and having a relative refractive index percent profile, Δ₁(r), and a minimum relative refractive index, Δ_2MIN, and the relative refractive index measured at a radius r=2.5 μm being −0.15≦Δ₁(r=2.5 μm) ≦0, and Δ_0MAX ≧Δ₁(r=2.5 μm);

(c) a fluorine doped second annular region surrounding and directly adjacent to the first annular core region and extending to a radius 13 μm ≦r₂≦30 μm and having a negative relative refractive index percent profile, Δ₂(r), with a minimum relative refractive index Δ_2MIN being:

Δ_2MIN<Δ₁(r=2.5 μm), and −0.7% ≦Δ_2MIN≦−0.28%; and

(ii) a cladding surrounding the core and having a relative refractive index percent Δ_c (r) in % measured relative to pure silica, and Δ_c (r)=Δ_2MIN±0.3%;

wherein the relative refractive index profile of the optical fiber is selected to provide attenuation of no more than 0.175 dB/km at the wavelength of 1550 nm.

A transparent conductive multilayer body of the present invention is characterized by having: a transparent film base; an SiO_x film (x is no less than 1.5 and less than 2) which is provided on one surface of the above described film base in accordance with a dry process, and has a thickness of 1 nm to 30 nm and a relative index of refraction of 1.6 to 1.9; an SiO₂ film which is provided on the above described SiO_x film and has a thickness of 10 nm to 50 nm; and a transparent conductive thin film which is provided on the above described SiO₂ film and has a thickness of 20 nm to 35 nm.

The present invention pertains to: a conductive sheet, a touch panel, a display device, a method for producing the conductive sheet, and a recording medium. In the present invention, the relative refractive index of a substrate with respect to a first protective layer, and/or the relative refractive index of the substrate with respect to a second protective layer is 0.86-1.15. The relative refractive index of a first substrate with respect to the first protective layer, and/or the relative refractive index of a second substrate with respect to the second protective layer is 0.86-1.15.

The invention relates to a high bandwidth multimode fiber used in an access network and a miniaturized optical device, which comprises a core layer and clad layers. The high bandwidth multimode fiber is characterized in that the radius of the core layer is 15 to 35 microns, the refractive index profile of the core layer is parabolic, and the maximum relative refractive index difference delta 1 percent max is over 0.8 percent; and the clad layers outside the core layer comprise an inner clad layer and/or a sunken inner clad layer, a rising ring and a sunken outer clad layer from the inside to the outside, and the relative refractive index difference of each layer satisfies the following relationships at the same time: delta 1 percent max is more than delta 2 percent which is more than delta 3 percent, delta 4 percent is more than delta 3 percent, the delta 4 percent is more than delta 5 percent, and the delta 4 percent is more than or equal to delta 2 percent. The macro-bending additional attenuation of the fiber is remarkably reduced, and the anti-bending performance of the fiber is improved; the fiber is provided with the rising ring so that the energy of some high-order mode of the core layer of the fiber is transferred or coupled to some mode of the rising ring from the core layer to effectively improve the bandwidth of the bending-insensitive multimode fiber; and the manufacturing method of the invention is simple, convenient and effective, and is suitable for mass production.

The present invention relates to a multi-core fiber having a structure for effectively suppressing crosstalk increase between cores caused by bending within an allowable range. The multi-core fiber comprises a plurality of types of cores respectively extending along an optical axis and a cladding region, and the effective refractive index of each core is set so that, in all pairs of cores of different types, a relative refractive index difference between an effective refractive index of a core of a certain type and an effective refractive index of a core of another type satisfies a condition regulated according to a core spacing between cores and a bending radius.

The present invention relates to an optical fiber which has a structure for further increasing an FOM (=|dispersion|/loss) and which can be applied to a dispersion compensation module. The optical fiber is mainly composed of silica glass and has a core region including a center of an optical axis, a depressed region surrounding the core region, a ring region surrounding the depressed region, and a cladding region surrounding the ring region and doped with F. As compared with the refractive index of pure silica glass, a relative refractive index difference of the core region is 3% or more but 4% or less, a relative refractive index difference of the depressed region is −1% or more but −0.5% or less, a relative refractive index difference of the ring region is 0.01% or more but 0.24% or less, and a relative refractive index difference of the cladding region is −0.3% or more but −0.1% or less. The FOM at the wavelength of 1550 nm is 250 ps/nm/dB or more.

A single-mode optical fiber, cable, cord, and a method for ensuring a service life of the fiber are provided. The fiber has a core and a cladding, the fiber having a cut-off wavelength that exhibits a single-mode transmission in a 1.31 μm wavelength band. A relative refractive index difference of the core with respect to the cladding is adjusted such that a bending loss, when a bend is applied in a radius smaller than a limit bending radius of the fiber, becomes greater than a detection limit value. The limit bending radius is calculated from a relationship between a bending radius applied to the optical fiber and a failure probability which occurs after a time period. The method includes measuring a loss and ensuring that a failure probability of the fiber during a service life falls within a failure probability used for setting the limit bending radius.

Multimode optical fiber is disclosed herein having a core surrounded by first and second annular cladding regions. The second annular cladding region has a maximum relative refractive index that is at least 0.05% higher than the minimum relative refractive index of the first annular cladding region.

An optical fiber having both low macrobend loss and low microbend loss. The fiber has a central core region, a first (inner) cladding region surrounding the central core region and having an outer radius r₂>16 microns and relative refractive index Δ₂, and a second (outer) cladding region surrounding the first cladding region having relative refractive index, 4₃, wherein Δ₁>Δ₃>Δ₂ . The difference between Δ₃ and Δ₂ is greater than 0.12 percent. The fiber exhibits a 22m cable cutoff less than or equal to 1260 nm, and r₁/r₂ is greater or equal to 0.24 and bend loss at 1550 nm for a 15 mm diameter mandrel of less than 0.5 dB/turn.

An optical fiber comprising: (I) a germania doped central core region having outer radius r₁ and (II) a maximum relative refractive index Δ_1max and a cladding region including (i) a first inner cladding region having an outer radius r₂>5 microns and refractive index Δ₂; (ii) a and a second inner cladding region having an outer radius r₃>9 microns and comprising refractive index Δ₃; and (iii) an outer cladding region surrounding the inner cladding region and comprising refractive index Δ₄, wherein Δ_1max>Δ₄, Δ₂>Δ₃, and wherein 0.01%≦Δ₄−Δ₃≦0.09%, said fiber exhibits a 22 m cable cutoff less than or equal to 1260 nm, and 0.25≦r₁/r₂≦0.85.