43results about How to "Reduce limit loss" patented technology

The present invention provides a microstructured hollow-core optical fiber. The optical fiber comprises first type medium circular tubes, second type medium circular tubes, and a third type medium circular tube; the first type medium tubes are nested in the second type medium circular tubes and are periodically distributed along the circumference of the second type medium circular tubes; intervalsbetween the outer walls of the adjacent first type medium circular tubes are greater than 0; the second type medium circular tubes are nested in the third type medium circular tube; and the first type medium circular tubes, the second type medium circular tubes and the third type medium circular tube are connected with one another in a tangent or intersecting manner. According to the microstructured hollow-core optical fiber of the invention, confinement loss can be lowered by simply increasing the number of the second type medium circular tubes, so that a difficulty that the confinement lossof a negative-curvature anti-resonant hollow-core optical fiber cannot be reduced by simply adopting a means of increasing annular layers which assists in reducing the confinement loss of a hollow-core photonic band gap optical fiber can be eliminated. According to the optical fiber provided by the invention, too many nodes will not be introduced into the cross section of the optical fiber, and anew scheme and idea can be provided for the design and manufacture of a broadband low-loss hollow-core optical fiber.

The invention discloses a panda-liked high birefringence photonic crystal fiber. A pair of large air holes are respectively replaced with seven small air holes; and the transverse space among the cladding air holes is different from the horizontal space among the cladding air hole; therefore, the structural fiber has duplicate rotational symmetry; the orthogonally polarizing mode is no longer degenerated, which appears high birefringence. The panda like type of high birefringence photonic crystal fiber can maintain single mode transmission within a wide wavelength range; the birefringence of the mode is one order of magnitude higher than the birefringence of the common fiber at least. The structural fiber has low restriction consumption, large numerical aperture and adjustable dispersion. Therefore, the PCF with the structure can be used for the manufacture of the polarization maintaining fiber and the related fiber device, which are provided with suitable dispersion and polarization characteristics. The invention has very small temperature influence and good stability.

The invention discloses a multi-resonance-layer hollow-core optical fiber, which comprises an annular dielectric pipe, wherein a first type hole is formed in the central position in the annular dielectric pipe; a plurality of groups of arc-shaped dielectric layers are arranged around the first type hole, a rectangular dielectric layer is arranged on the inner side of each arc-shaped dielectric layer; a second type hole is formed between every two groups of arc-shaped dielectric layers in the same arc direction; third type holes are formed between each rectangular dielectric layer and the innerwall of the annular dielectric pipe and between each rectangular dielectric layer and the corresponding arc-shaped dielectric layer, a fourth type hole is formed between every two groups of adjacentrectangular dielectric layers, the first type hole, the second type holes, the third type holes and the fourth type holes form a low-refractive-index region, and the arc-shaped dielectric layers, therectangular dielectric layers and the annular dielectric pipe form a high-refractive-index region. The multi-resonance-layer hollow-core optical fiber has the beneficial effects that the damage threshold of the optical fiber is improved; the confinement loss of the optical fiber is reduced, and the low confinement loss features can be obtained conveniently; and high-bandwidth and low-loss opticaltransmission can be obtained in a facilitated manner.

A hollow negative curvature photonic crystal fiber with high birefringence and low loss comprises an optical fiber tube body which has a circular cross section and is hollow inside. The tube wall of the optical fiber tube body comprises inner and outer layers of circular ring structures. Two large capillary tubes internally tangent to an optical fiber interlayer are arranged in the hollow core ofthe optical fiber tube body in a bilateral symmetry manner. Three small capillary tubes which are internally tangent to the optical fiber interlayer and are the same are arranged in the hollow core ofthe optical fiber tube body above and below the space between the two large capillary tubes. A medium capillary tube internally tangent to the corresponding large capillary tube is arranged in each of the two large capillary tubes. The small capillary tubes, the medium capillary tubes and the large capillary tubes are bilaterally symmetrical. A light wave transmission cavity defined by the smallcapillary tubes and the large capillary tubes is formed in the center of the hollow core of the optical fiber tube body. The optical fiber tube body, the large capillary tubes, the medium capillary tubes and the small capillary tubes are all made of silica glass. The optical fiber is simple in structural design, the adjustable range of capillary structure parameters is large, and industrial preparation and commercial application of HCF can be achieved.

The invention relates to an air hole square array fiber core annular doping four-core photonic crystal fiber, which comprises a fiber cladding and fiber cores, wherein the fiber cladding is formed by distributing a plurality of layers of air hole square arrays; the fiber core is formed by four groups of units lack of air holes; and the four fiber cores are symmetrically distributed at diagonal lines of four quadrants. Each fiber cores comprises an inner core and a doping annular area, wherein the inner core and the fiber cladding are made of quartz materials, and the doping annular area wrapped outside the inner core is made of quartz doped with an oxide capable of increasing a refractive index, so that the refractive index of the doping annular area is a little higher than that of the fiber core. With the adoption of the fiber core annular doping four-core structure, the mode area can be efficiently increased, and the nonlinear effect can be reduced. The fiber core annular doping can form a flat mode field, thereby efficiently reducing the thermal damage effects of the fiber. The fiber cladding is formed by distributing the plurality of layers of air hole square arrays, so that the ultralow limit loss can be realized, and the energy loss can be greatly reduced in the transmitting process.

The invention provides an anti-resonance hollow-core optical fiber. The anti-resonance hollow-core optical fiber is composed of a first-type dielectric tube, a second-type dielectric tube and a first-type dielectric layer and comprises a cladding region with high refractive index and a fiber core region with low refractive index; the first-type dielectric tube and the first-type dielectric layer are both connected to the second-type dielectric tube; the area surrounded by the outer wall, close to the core region, of the first type dielectric tube is a fiber core region (a first-type hole); a second-type hole is isolated between the first-type dielectric tube and the first-type dielectric layer; and a third-type hole is isolated between the first-type dielectric tube and the second-type dielectric tube. The fiber core of the optical fiber has a negative curvature boundary; the optical fiber is provided with a plurality of anti-resonance layers; the cladding of the optical fiber has no nodes, so that the leakage loss is effectively reduced; the optical fiber has no loss peak value caused by transverse nodes, so that transmission bandwidth is increased; besides, optical fiber modes are mainly distributed in air holes, so that the material absorption loss of the optical fiber can be effectively reduced, the damage threshold of the optical fiber is improved, and high-power laser and terahertz waves can be effectively transmitted.

The invention relates to the technical field of optical fiber communication, and discloses a double-layer weak-coupling few-mode hollow anti-resonance optical fiber which comprises an outer wrapping area and a fiber core area. The fiber core area is arranged in the outer wrapping area, and the fiber core area and the outer wrapping area are concentric circles; the outer wrapping area comprises an outer wrapping layer, a plurality of second-layer nested tubes and a plurality of first-layer anti-resonance tubes; the second-layer nested tubes are internally tangent to the outer wrapping layer; the first-layer anti-resonance tubes are located between the second-layer nested tubes and the fiber core area and are tangent to the second-layer nested tubes and the fiber core area respectively; the plurality of second-layer nested tubes are uniformly and circumferentially distributed at equal intervals and surround the fiber core area; and the plurality of first-layer anti-resonance tubes are arranged at equal intervals, are uniformly and circumferentially distributed and surround the fiber core area. The problems that an existing optical fiber lacks flexible optimization capacity and does not support few-mode weak coupling transmission, and the limited loss of a transmission mode is large are solved.

The invention discloses a hollow-core anti-resonance optical fiber with a ginkgo leaf-shaped cladding. The hollow-core anti-resonance optical fiber sequentially comprises an optical fiber outer sleeve, ginkgo leaf-shaped cladding tubes and an air fiber core from outside to inside; the ginkgo-leaf-shaped cladding tubes meet the anti-resonance reflection waveguide (ARROW) principle in design and are specifically made of glass, the thickness of the ginkgo-leaf-shaped cladding tubes is t, the whole ginkgo-leaf-shaped cladding tubes are in a neat ginkgo leaf shape after winding and are specifically composed of a front arc section and two rear arc sections, the front arc section and the rear arc sections have negative curvature relative to the air fiber core and bend towards the outer side of the air fiber core; and the plurality of ginkgo leaf-shaped cladding tubes are fixed on the optical fiber outer sleeve in a rotational symmetry manner.

The invention discloses a nested type hollow-core anti-resonance optical fiber with a crescent-shaped cladding. The nested type hollow-core anti-resonance optical fiber comprises an optical fiber outer sleeve, a circular nested cladding tube, crescent-shaped outer cladding tubes and an air fiber core from outside to inside in sequence; the circular embedded cladding tube and the crescent-shaped outer cladding tubes meet the anti-resonance reflection waveguide (ARROW) principle in design and are specifically made of silicon dioxide, and the thickness of the circular embedded cladding tube and the crescent outer cladding tubes is t; in the cladding region, a plurality of crescent cladding tubes with circular embedded sleeves are arranged at certain intervals in a surrounding manner to form the cladding region, and a central region surrounded by the boundary of the crescent cladding tubes is an air fiber core region.