32results about How to "Reduce the attenuation factor" patented technology

The invention relates to a low-attenuation bending insensitive single-mode optical fiber for an optical communication transmission system. The optical fiber comprises a core layer and a cladding layer. The optical fiber is characterized in that the refractive index of the core layer is distributed according to an alpha-order parabola, and the distribution index alpha is 1.5-9.0; the cladding layer is sequentially formed by an inner cladding layer, an intermediate cladding layer and an outer cladding layer from inside to outside; the maximal refractive index difference delta 1 of the parabola core layer is 0.25-0.45 percent, and the radius R1 of the core layer is 5.0-7.0mu u; the relative refractive index different delta 2 of the inner cladding layer is -0.20-0 percent, and the radius R2 of the inner cladding layer is 7.0-10.0mu m; the relative refractive index difference delta 3 of the intermediate cladding layer is -0.20-0 percent, and the radius R3 of the intermediate cladding layer is 10.0-20.0mu m; and the outer cladding layer is a pure quartz glass layer. The low-attenuation bending insensitive single-mode optical fiber has reasonable refractive index section design and low doping amount, and has excellent attenuation resistance and bending resistance.

The invention discloses a low-loss optical fiber and a manufacturing method of the low-loss optical fiber, and relates to the field of optical fibers. The low-loss optical fiber comprises a step change waveguide; the step change waveguide comprises a core layer, a core cladding transition layer, a core cladding interface transition layer, a deep fluorine-doped cladding, a cladding sleeve transition layer, a cladding sleeve interface transition layer and a sleeve layer, wherein the core layer, the core cladding transition layer, the core cladding interface transition layer, the deep fluorine-doped cladding, the cladding sleeve transition layer, the cladding sleeve interface transition layer and the sleeve layer are arranged in sequence from inside to outside; the core layer is made of a pure silicon core slightly doped with fluorine or boron, wherein the relative refringence between the core layer and the pure silicon core is 0-0.1%; the deep fluorine-doped cladding is made of pure silicon dioxide deeply doped with fluorine, wherein the relative refringence between the deep fluorine-doped cladding and the core layer is 0.24%-0.28%; the refractivity in the core cladding transition layer is distributed in a gradient change mode according to a parabola curve, wherein the range of the absolute value of stress coefficients is from 0.005 to 0.015; the base point temperature rises gradually from 900-950 DEG C to 1150-1200 DEG C. The attenuation coefficient of the low-loss optical fiber manufactured according to the manufacturing method can be reduced to less than 0.158 dB/km in a 1550 nm wave band.

The invention relates to a single mode fiber with the lower manufacturing cost. The single mode fiber comprises a core layer, wherein a first inner wrapping layer, a second inner wrapping layer and an outer wrapping layer wrap the core layer in sequence. The single mode fiber is characterized in that the outer wrapping layer is made of natural siliceous sand, the absolute refraction index of the outer wrapping layer ranges from 1.4572 to 1.4574, the diameter alpha of the core layer is 8-10 micrometers, the refraction index difference delta n1 of the core layer and the outer wrapping layer ranges from 4.1*10<-3> to 6.4*10<-3>, the ratio b/a of the diameter b of the first inner wrapping layer to the diameter a of the core layer is greater than or equal to 1.6, the refraction index difference delta n2 of the first inner wrapping layer and the outer wrapping layer ranges from -2.4*10<-3> to -0.7*10<-3>, and the ratio c/a of the diameter c of the second inner wrapping layer to the diameter a of the core layer is greater than or equal to 3.6. The outer wrapping layer of an optical fiber prefabricated bar is made of the natural siliceous sand with the lower cost, so that the manufacturing cost of the optical fiber is lowered greatly; the structure of the inner wrapping layers and the outer wrapping layer is adopted, the ratio of the inner wrapping layers to the core layer is selected reasonably, and the fluorine mixing amount and the chloride ion concentration in the second inner wrapping layer are controlled, so that influence on optical attenuation from the impurities of the outer wrapping layer made of the natural siliceous land is reduced, and the water peak performance and the attenuation coefficient of the single mode fiber are reduced effectively.

The invention relates to a single mode fiber with a low damping coefficient. The single mode fiber with the low damping coefficient comprises a core layer and a cladding layer and is characterized in that the radius r1 of the core layer is 3.9-4.6Mum, the relative index of refraction delta1of the core layer is 0.08%-0.24%, the core layer covers an inner cladding layer, an concaving inner cladding layer, an auxiliary outer cladding layer and an outer cladding layer from interior to exterior, wherein the radius r2 of the inner cladding layer is 8-15Mum, the relative index of refraction delta2 of the inner cladding layer is-0.30 %--0.05 %,the radius r3 of the concaving inner cladding layer is 14-20Mum, the relative index of refraction delta3 of the concaving inner cladding layer is -0.6 %--0.2 %, the radius r4 of the auxiliary outer cladding layer is 35-50Mum, and the relative index of refraction delta4 of the auxiliary outer cladding layer ranges from -0.35 % to -0.05 %. The outer cladding layer is a pure silicon dioxide glass layer. The single mode fiber with the low damping coefficient has the advantages that the damping coefficient of a fiber is reduced, and through the reasonable design on the section face of each core and cladding layer of the fiber, the fiber is provided with a MFD equal to or larger than 8.7Mum; the section face of the fiber adopts a multilayer step-pattern concaving cladding structure, the wide cladding structure is used for limiting fundamental mode reveal, and a good improvement function on the bending loss of the fiber is achieved.

The invention relates to a low attenuation gradient orbital angular momentum fiber. The low attenuation gradient orbital angular momentum fiber includes a core layer and a cladding layer; the core layer radius R1 is 3.5 [Mu]m to 5.5 [Mu]m, and the [Delta]1 is -0.08% to 0.08%; the core layer is covered by a ring core layer, a depressed cladding layer and an outer cladding layer; the ring core layerhas a gradual shape, and the top portion has a gradual concave shape, and is successively divided into an inner ring layer, a lower concave layer and an outer ring layer from the inside to the outside; the inner ring layer has a radius R2 of 4.5 [Mu]m to 6.5 [Mu]m and a [Delta]2 of 0.7% to 1%; the lower concave layer radius R3 is 8 [Mu]m to 13 [Mu]m, and the [Delta]3 is 0.6% to 0.9%; the outer ring layer has a radius R4 of 9[Mu]m to 15[Mu]m and a [Delta]4 of 0.7% to 1%; and the depressed cladding layer radius R5 is 11 [Mu]m to 16 [Mu]m, and the [Delta]5 is 0.6% to 0.3%; the relative refractive index difference is the relative refractive index difference between each layer of the fiber and the outer cladding layer; and the outer cladding layer is an outer cladding layer with a negative refractive index relative to a pure silicon dioxide layer. The low attenuation gradient orbital angular momentum fiber not only can support long-distance signal transmission with low attenuation of fourmode groups, but also has good comprehensive performances in crosstalk of the optical fiber, macro-bend and micro-bend loss of each mode and the like.

The invention relates to a multi-core optical fiber, which comprises a plurality of core layers and a common outer cladding layer, and is characterized in that the number of the core layers is eight,and the core layers are uniformly distributed along the circumferential direction at equal intervals; the distance between every two adjacent core layers is 28-33 mum; each core layer is sequentiallycoated with an inner cladding layer and a sunken cladding layer from inside to outside; the eight-core homogeneous single-mode optical fiber is formed; the radius R1 of the core layer is 3.8 to 4.2 mum; the relative refractive index difference delta1 of the core layer relative to the common outer cladding is 0.36%-0.40%; the radius R2 of the inner cladding is 5-8 mum; the relative refractive indexdifference delta2 of the inner cladding layer relative to the common outer cladding layer is -0.05% to 0.05%; the radius R3 of the sunken cladding is 8-12 mum, the relative refractive index difference delta3 of the sunken cladding relative to the common outer cladding is -0.7%-0.9%, and the relative refractive index difference delta4 of the common outer cladding relative to pure silicon dioxide is -0.4%-0%. The optical fiber can be transmitted in an O waveband and a C waveband, space division multiplexing dimension density is kept, the optical fiber can be compatible with an existing device,and the comprehensive performance such as crosstalk of the optical fiber and macrobend and microbend losses of all channels is made to be in a good level.

The invention relates to a single-mode optical fiber with ultralow loss and large effective area and a preparation method thereof. The optical fiber sequentially comprises an inner core layer, a sunken core layer, an outer core layer, an inner cladding layer, a sunken cladding layer and an outer cladding layer from inside to outside, wherein the inner core layer, the sunken core layer, the outer core layer, the inner cladding layer and the sunken cladding layer take silicon dioxide as a substrate material and are added with a dopant, and the outer cladding layer is pure silicon dioxide; and wherein the relative refractive index of the inner core layer is delta n1, the relative refractive index of the sunken core layer is delta n2, the relative refractive index of the outer core layer is delta n3, the relative refractive index of the inner cladding layer is delta n4, the relative refractive index of the sunken cladding layer is delta n5, and the magnitude of the relative refractive indexes are as follows: delta n1>delta n3>delta n2>delta n4>delta n5, and the material is prepared by adopting an MCVD process and an OVD process. The optical fiber of the invention has good comprehensiveperformances such as effective area, cut-off wavelength, attenuation, dispersion, bending loss and the like.

The invention relates to a step ultralow-attenuation dual-mode optical fiber comprising a core layer and a cladding layer. The core layer has a radius R1 from 4.5 to 14 micrometers and a relative refractive index difference [delta]1 from -0.05% to 0.15%, and is successively wrapped in, from inside to outside, an inner cladding layer, a recessed inner cladding layer, an auxiliary outer cladding layer and the outer cladding layer. The inner cladding layer has a radius R2 from 9 to 18 micrometers, and a relative refractive index difference [delta]2 from -0.4% to -0.15%. The inner cladding layer has a radius R3 from 14 to 23 micrometers and a relative refractive index difference [delta]3 from -0.8% to -0.3%. The auxiliary outer cladding layer has a radius R4 from 37 to 50 micrometers and a relative refractive index difference [delta]4 from -0.6% to -0.25%. The outer cladding layer is a pure silica glass layer. The optical fiber supports the propagation of two LP modes including LP01 and LP11 on the C-band. The optical fiber can support long-distance signal transmission in two modes, and each mode has a low attenuation coefficient. The optical fiber is low in manufacturing cost, and thecomprehensive performances such as bending loss and dispersion of the optical fiber is at a good level in the stress band.

The present invention discloses a compound semiconductor integrated optical fibre-optic gyro chip. Its waveguide upper cladding and lower cladding are made up by using double heterojunction or single heterojunction epitaxial material, its substrate is compound semiconductor material, and the internal breakout position of Y branch waveguide is formed into semi-rectangular or semi-elliptical form, its external breakout position adopts fold line or curved line. Between the connected corner position of Y branch waveguide output and horizontal arm and horizontal branch arm a transition structure is added, in said structure the beam is expanded firstly, then the beam is contracted, then said structure is connected with the horizontal branch arm. Said integrated optical chip mainly uses one Y branch waveguide as power divider, and uses two phase modulators, at the same time, uses them as TE/TM mode polarizer. Said phase modulator adopts upper and lower electrodes structure, said upper electrode can be directly covered on the ridge waveguide.

The present invention relates to a large-scale low-attenuation optical fiber preform and a preparation method thereof. A preformed core rod including an inner core layer, an outer core layer, an innercladding layer and a depressed layer is prepared by an MCVD process, a first outer cladding layer loose body is deposited by a VAD process, and first sintering treatment is carried out, so that a first optical fiber preform is prepared; and a second outer cladding layer loose body is deposited by an OVD process, and secondary sintering treatment is carried out, so that the optical fiber preform is obtained. The diameter of the optical fiber preform prepared by the method of the invention can reach 215 mm, the length of a single preform can reach 2930 km, the attenuation of the fiber at 1310 nm is as low as 0.298 dB/km, the attenuation coefficient at 1383 nm is as low as 0.265 dB/km, the attenuation coefficient at 1550 nm is as low as 0.165 dB/km, and the fiber cut-off wavelength is 1265 nm to 1273 nm.

The invention relates to a gradient-type ultra-low-attenuation four-mode optical fiber. The gradient-type ultra-low-attenuation four-mode optical fiber includes a core layer and a cladding. The diameter R1 of the core layer is 9.8-20 micrometers. The core layer has a refractive index in parabolic distribution and Alpha is in a range between 1.95 and 2.10. The maximal core layer relative reflectiveindex difference Delta1 is in a range between -0.05% and 0.2%. The core layer includes a wrapping inner cladding, a sunken inner cladding, an auxiliary outer cladding and an outer cladding. The diameter R2 of the inner cladding is 13 to 23 micrometers. Delta 2 is in a range between -0.4% and -0.15%. The diameter R3 of the sunken inner cladding is in a range between 16 and 26 micrometers. Delta3 is in a range between -0.8% and -0.3%. The diameter R4 of the auxiliary outer cladding layer is in a range between 37 and 50 micrometers. Delta4 is in a range between -0.6% and-0.25%. The outer cladding is a pure silicon dioxide glass layer. The optical fiber supports propagation in four LP mode in a C waveband: LP01, LP11, LP21 and LP02. The invention supports long range signal transmission in thefour modes and each mode has a comparatively low attenuation index, so that combination property including bending loss, chromatic dispersion and the like of the optical fiber can be in a good levelin a stress waveband.

The invention belongs to the technical field of display devices and particularly discloses a backlight module and an obtained liquid crystal display television. The backlight module comprises at least one PCB lamp panel, a backlight source, at least one wide-angle lens, a piece of reflection paper, a diffusion panel and at least one optical membrane, wherein the backlight source is a monochromatic light source. The backlight module has the advantages of being high in brightness and wide in color gamut, the liquid crystal display television obtained through the backlight module has the advantages of being high in brightness and light energy utilization rate, in addition, the design difficulty of the obtained liquid crystal display television is lowered, the production requirement is lowered, and cost is reduced.

The low-loss flexible feeder coaxial cable comprises an inner conductor layer, an insulating layer, an outer conductor layer and a sheath layer which are sequentially arranged from inside to outside, and the inner conductor layer, the insulating layer, the outer conductor layer and the sheath layer are coaxially arranged and connected with one another. The outer conductor layer and the inner conductor layer are both of a regular spiral embossed copper pipe structure, the insulating layer is a large-foaming-degree polyolefin foaming insulating layer, low direct-current resistance and low insulating dielectric constant can be kept, the transmission loss of the cable is greatly reduced, and the bending performance of the cable is optimized. The technical field of coaxial cables is adapted.