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

The invention discloses a supermode microstructure optical fiber for transmitting orbital angular momentum. The supermode microstructure optical fiber comprises: a central air hole, a substrate material, a ring array fiber core area and a cladding layer area, wherein the circle center of the central air hole is located at the center of the optical fiber, the ring array fiber core area comprises anoptical fiber substrate and a plurality of doped quartz columns uniformly arranged along the central air hole, the cladding layer area is located on the outer side of the ring array fiber core area and share the circle center with the central air hole, the cladding layer area is a circular microstructure cladding layer composed of a first cladding layer, a second cladding layer, a third claddinglayer and a fourth cladding layer, wherein the first cladding layer, the second cladding layer, the third cladding layer and the fourth cladding layer are respectively composed of 42, 48, 54 and 60 circular air holes which are annularly and uniformly arranged. The working wavelength range of the optical fiber disclosed by the invention is 1.0 to 1.8 um, 60 orbital angular momentum modes can be supported within the working wavelength range, the limiting loss of the modes is low, the dispersion is small, and the effective mode area is large.

This invention relates to all solid band gap fibers with a restricted low loss and low bending loss, which includes a core-layer and a cladding layer, the features are: the cladding materials have a refractive index n1, and the basic units with high doped materials with a refractive index n3, which locates on the regular mesh nodes of the cladding layer, and the high doping region of each basic unit are wrapped around with at least one belt region at a low refractive index n2. The invention can be widely applied in the field of photonic optical devices, for instance the fiber amplifier and fiber laser of rare earth doping, and writing for fiber grating etc.

The invention discloses a novel photonic crystal fiber capable of transmitting a plurality of OAM (orbital angular momentum) modes. The novel photonic crystal fiber comprises a central fiber core, an annular high-refraction-index layer, a first coating layer, a second coating layer, a third coating layer and a fourth coating layer, wherein the central fiber core utilizes round air holes, and the central fiber core is covered by the annular high-refraction-index layer; the first coating layer is composed of 36 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 1; the second coating layer is composed of 40 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 2; the third coating layer is composed of 45 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 3; the fourth coating layer is composed of 50 square air holes, and a rotation angle of adjacent air holes around the circle center is theta 4; a substrate material of each coating layer is quartz, the square air holes of all the coating layers are the same in size, the distances between the adjacent coating layers are the same, and the coating layers are symmetrically distributed in a round shape around the central fiber core. The novel photonic crystal fiber can support as many as 58 OAM modes, can transmit a plurality of HE and EH modes and can remarkably improve optical communication capacity.

The present invention provides an anti-resonant hollow-core optical fiber. The optical fiber is composed of a first-type dielectric tube, a second-type dielectric tube and a first-type dielectric layer, including a high-refractive-index cladding region and a low-refractive-index core region. Both the first-type medium pipe and the first-type medium layer are connected to the second-type medium pipe. The area surrounded by the outer wall of the first-type dielectric tube close to the core region is the fiber core area (the first-type hole). A second-type hole is isolated between the first-type medium pipe and the first-type medium layer, and a third-type hole is isolated between the first-type medium pipe and the second-type medium pipe. The fiber core has a negative curvature boundary, the fiber has multiple anti-resonant layers, and the fiber cladding has no nodes, which effectively reduces the leakage loss, and the fiber has no loss peaks caused by lateral nodes, which increases the transmission bandwidth. In addition, the fiber modes are mainly distributed in air holes, which can effectively reduce the material absorption loss of the fiber, increase the damage threshold of the fiber, and effectively transmit high-power laser and terahertz waves.

A negative curvature of the empty core with high dual -refractive low loss, a photonic crystal fiber, including the cross -section of the fiber tube with a circular and internal empty core, the tube wall of the fiber tube includes two layers of ring structure, the fiber tube body body, the fiber tube bodyThere are two large hair tubes that are cut into the fiber -fiber expansion in the left and right symmetry in the empty core, and the two large fiber tubes are set up between the upper and lower fiber tubes below and below.In the small capillary tube, both large capillary tubes are set in a medium -capped tube that is cut into the large capillary tube. Small hairy tubes, medium hair thin tubes, and large hair fine tubes are symmetrical.The optical wave transmission of the cavity, fiber tube, large capillary tubes, medium capillary tubes, and small capillary tubes are made of silicon glass.This optical fiber structure is simple, and the capacity of the capillary structure can be adjusted in a large range, which is conducive to the realization of HCF industrial preparation and commercial applications.

The invention discloses a high double-refraction chromatic dispersion adjustable pohotonic crystal fiber. The high double-refraction chromatic dispersion adjustable pohotonic crystal fiber comprises a substrate material, a fiber core, rectangular arranged medium holes and regular triangle lattice arranged medium holes, wherein the fiber core, the rectangular arranged medium holes and the regular triangle lattice arranged medium holes are distributed from inside to outside, a center that defines an end face of the optical fiber serves as a circle center, an X axis is parallel to long side directions of a rectangle that the rectangular arranged medium holes correspond to, a Y axis is parallel to short side directions of the rectangle that the rectangular arranged medium holes correspond to, the X axis and the Y axis pass through the circle center, the fiber core, the rectangular arranged medium holes and the regular triangle lattice arranged medium holes are symmetrical along the circle center respectively, five medium holes are designed in the long sides of the rectangle, three medium holes are designed in the short sides of the rectangle, and positions which are adjacent to second and fourth medium holes of the long sides of the rectangle in the Y axis direction are free of medium holes in terms of the regular triangle lattice arranged medium holes. The high double-refraction chromatic dispersion adjustable pohotonic crystal fiber has the advantages of high double refractions and low confinement loss, and hole intervals and medium hole sizes can be adjusted so that adjustment of large negative dispersion and zero dispersion wave lengths can be achieved.

The invention discloses a photonic crystal fiber capable of transmitting 22 photon angular momentum modes. The photonic crystal fiber comprises a center fiber core, an annular high refractive index layer and an annular cladding, wherein the fiber core is a large air hole; the annular cladding comprises a cladding I, a cladding II, a cladding III and a cladding IV; the cladding I is composed of 36 square air holes in a circular uniform arrangement manner, and an included angle between every two adjacent square air holes relative to the center of a circle of a cross section of the optical fiber is 10 degrees; the cladding II is composed of 30 circular air holes in a circular uniform arrangement manner, and an included angle between every two adjacent square air holes relative to the center of a circle of the cross section of the optical fiber is 12 degrees; the cladding III is composed of 36 circular air holes in a circular uniform arrangement manner, and an included angle between every two adjacent square air holes relative to the center of a circle of the cross section of the optial fiber is 10 degrees; and the cladding IV is composed of 40 circular air holes in a circular uniform arrangement manner. According to the photonic crystal fiber disclosed by the invention, the quantity of OAM (Orbital Angular Momentum) modes supported by a waveband of 1500-1600nm reaches 22, crosstalk among the various modes is less, confinement loss of most of the modes is low (10<7>dB / m), and the photonic crystal fiber is small in dispersion and low in nonlinear coefficient.

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.