38results about How to "Low nonlinear coefficient" patented technology

The invention discloses a double-coating large-mode-area photon crystal flysecond laser directly obtaining micro joule-level single pulse energy, belonging to the field of laser technique and nonlinear optics, where the laser main body is based on double-coating large-mode-area photon crystal optical fiber of polarization-protection structure and adopts high-power LD laser to directly pump; the laser uses grating pair to compensate dispersion, starts mode locking with the help of semiconductor saturable absorber mirror (SESAM), and controls polarization by wave plate and polarization beam splitter and implements tunable output; laser resonant cavity keeps net positive dispersion inside and runs in self-similar mode locking mode and outside-cavity dispersion compensation is made on the output pulse and the pulse is 100-200fs wide. And the advantages: the laser has good stability, and the output pulse has high energy and high repeating frequency. And the invention can effectively avoid split of pulse running at high energy.

The piezoresistor is fabricated by agglutinating interleaved ZnO porcelain and inner electrode. Main material of the ZnO porcelain is ZnO powder in sub micro of average particle diameter 0.10-0.99 micro. The inner electrode layer is made from palladium and argentine, and palladium is in 3-10% (Wt%) and argentine is in 990-97%. Agglutinating temp is 900-980 deg.C. The invention also discloses method for manufacturing the piezoresistor.

The present invention disclosed a photon crystal fiber that actively filter except for high -order radial mode, including the first air circular hole, high refractive index ring, second air round hole, third air circular hole, third air circular hole, and third air circular hole set from the inside to the outside.The fourth air round hole and optical fiber pack; the first air round hole is located in the center of the cross -section of the fiber; the number of air circular holes, the third air round hole, and the fourth air round hole are the same, and each layer of air hole is the same, and from small to large mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual mutual.Embeds.The present invention supports up to 226 OAM modes at 1.5 μm, and supports 208 OAM modes at 1.55 μm at 1.55 μm, which greatly increases the capacity of the communication system. By increasing the radius of the packet layer, the invention maintains the thickness, Can effectively suppress the high -level radial mode, but also reduce the impact of the purity of the OAM mode; the present invention has the advantages of inhibiting inter -model bruises and low non -linear coefficients. It is suitable for high -capacity OAM mode sub -communication systems.Application value.

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 present invention proposes a low nonlinear coefficient few-mode optical fiber with a depressed refractive index cladding, which realizes supermode operation with large effective mode field area, low nonlinear coefficient, high mode field density, and low differential mode group delay; and The nonlinear coefficient and differential mode group delay are flat in the C-band range; the mode field characteristics of the supermode in the fiber can be changed by changing the size, position and refractive index distribution of the ring; it can be applied to fiber optics, fiber optic communications, fiber optics Wireless access, optical information processing and new generation information technology and other fields.

The invention discloses combined In3+ and Ga3+ donor doped ZnO varistor ceramic and a preparation method thereof; the combined In3+ and Ga3+ donor doped ZnO varistor ceramic comprises a base material and a doping material, wherein the base material comprises, by weight, 87-95 parts of ZnO, 2.0-4.0 parts of Bi2O3, 0.4-0.7 part of MnO2, 1.5-3.5 parts of Sb2O3, 0.5-1.5 parts of Co2O3, 0.2-1.0 part of Cr2O3, and 1-5 parts of seed crystal doping material; the seed crystal doping material comprises ZnO, Ga2O3 and In2O3 having a mass ratio of (90-95):(0.1-5):(0.1-5). The combined In3+ and Ga3+ donor doped ZnO varistor ceramic has the advantages that ZnO grain resistivity can be decreased and ZnO lattice distortion can be controlled, and also has the advantages of low finish ZnO varistor residue long ageing life and high pulse current tolerance.

The invention relates to an air-core polarization maintaining photonic crystal optical fiber. Along a circle of the inner wall of a glass tube, a plurality of micro capillaries are arranged to form a pore inner covering layer area, the peripheral part of the pore inner covering layer area and the contact part of the inner wall of the glass tube are fixed on the inner wall of the glass tube in a welding mode, the middle part of the pore inner covering layer area is a low refractive index fiber core I, namely a fiber core area, and the two sides of the fiber core area are low refractive index fiber cores II, namely seven-cell pores; the two sides in the fiber core area are gap areas which are enveloped by symmetrical fiber cores; or the upper side and the lower side in the fiber core area are symmetrically provided with convex areas which are enveloped by two fiber cores; or the two sides in the fiber core area are the gap areas which are enveloped by the fiber cores, and the upper side and the lower side in the fiber core area are symmetrically provided with the convex areas which are enveloped by the two fiber cores. The polarization maintaining performance, low-loss transmission and single-model advantages can be achieved, and the air-core polarization maintaining photonic crystal optical fiber has the advantages of being high in temperature stability, low in non-linear coefficient, low in magnetic field sensitivity, good in irradiation resistance and the like.

The invention discloses a lightning surge protection composite piezoresistor and a manufacturing method thereof. The varistor is composed of a lightning protection valve chip and a sensitive pressure sensitive chip connected in parallel. The lightning protection valve chip uses a varistor chip with a large current peak value, a low mutation minimum resistance, and a nonlinear coefficient of 45 to 55. The sensitive varistor chip uses a varistor chip with a high nonlinear coefficient and a work-resistant Frequency overvoltage varistor chip. When a small current surge fluctuates in the line due to operation overvoltage or transient overvoltage, the sensitive varistor chip plays the main role and releases the energy immediately. When lightning overvoltage occurs, due to the impact voltage amplitude High and high energy. At this time, the lightning protection valve chip plays the main role, releasing the energy at the first time, so as to ensure the stability of the transmission line. The invention has the advantages of realizing the effective lightning protection and anti-surge impact of the transmission line, greatly prolonging the service life of the product and ensuring the reliability of the product.

The invention discloses a hollow-core photonic crystal fiber resonant gyroscope based on free-form surface lens coupling. In the present invention, the light emitted by the narrow-linewidth laser light source passes through the first polarization-maintaining optical fiber and then modulated by the phase modulator to reach the Y waveguide. The Y waveguide divides the light into two beams of light with equal light intensity. After the circulator exits from the corresponding second polarization-maintaining fiber, it passes through the free-form surface lens coupler and the polarization beam splitting prism to couple and then enters the hollow-core fiber ring; a part of the light in the hollow-core fiber ring is reflected by the free-form surface lens coupler in the Resonance occurs in the ring of the hollow-core fiber ring, and another part of the light in the hollow-core fiber ring passes through the free-form surface lens coupler and then returns to the second polarization-maintaining fiber, passes through the corresponding circulator, and then reaches the corresponding photodetector. The invention has high integration, fewer coupling parts, reduces relative position error between components, has a more compact overall structure, improves the reliability and environmental adaptability of the fiber optic gyroscope, and has simple manufacturing process and high stability.

The present invention proposes a three-mode mode division multiplexer with low loss, low crosstalk and graded refractive index distribution, which consists of three identical transmission channels, one of which is the main transmission channel; the radius of the transmission channel is 20 μm, and the core and cladding of the transmission channel The refractive index difference is 0.0015, and the cladding refractive index is 1.442524; the refractive index from the center of the channel core to the cladding changes gradually; the mode LP01 is directly input into the main transmission channel; the mode LP11a and LP11b channels are respectively placed in the main transmission channel cross section x and y In the direction, the channel length is 33mm, and the distance from the main channel is 6μm; in the 1400nm‑1700nm band, the coupling efficiency of the multiplexer is better than ‑0.479dB; the three modes of refractive index gradient distribution, low loss and low crosstalk are realized Modulus multiplexing.

The invention provides an open microstructured fiber having a composite fiber core and using shifted single-hole diversion, and the open microstructured fiber provided by the invention comprises a fiber core and a cover layer, wherein the cover layer is compatible with the design of the band-gap cover layer of the traditional total internal reflection type microstructured fiber, and a composite structure and a diversion structure are respectively introduced into the fiber core and the cover layer. The open microstructured fiber provided by the invention is characterized in that an oval diversion hole passing through a band-gap structure at one side is arranged at one side of the axisymmetric line of the surrounded band-gap structure, and a synthetic fiber core consisting of three small round air holes distributed in the shape of an inverted triangle is arranged around the fiber core. The open microstructured fiber provided by the invention has the characteristics of simplicity for manufacturing, easiness for implementation and excellent real-time sensing effectiveness, and can be applied to the real-time sensing of gas-liquid two-phase fluid of fibers and related fields.

The invention discloses a photonic crystal fiber. The fiber comprises a core layer, a covering layer and a coating layer from the interior to the exterior. The cross section of the fiber is circular.The core layer, the covering layer and the coating layer are concentric. The core layer is arranged in the innermost layer. A circular hole is arranged in the center of the cross section of the core layer. Multiple elliptic air holes are uniformly arranged in the covering layer. The covering layer comprises 5 covering layer rings. The air holes in each covering layer ring are arranged in an annular array manner by taking the center of the core layer as the center original point. The size of the area of the cross sections of the air holes in the covering layer rings are successively increased from the inner ring to the outer ring. Long shafts of the elliptic air holes point to the center of the core layer. The intervals between the covering layer rings are successively increased from the inner ring to the outer ring. The core layer and the covering layer are made of silicon dioxide crystals or silicon crystals. The coating layer is made of acrylic ester or silicone rubber. According tothe invention, multiple orbital angular momentum modes can be transmitted; the effective refractivity reach 10-3 orders; the confinement loss is low; the nonlinear coefficient is small; and the chromatic dispersion is low.

The invention discloses In<3+> and Nb<5+> composite donor-doped ZnO voltage-sensitive ceramic and a preparation method thereof. The voltage-sensitive ceramic comprises base materials and doping materials. The base materials contain, by weight, 87-95 parts of ZnO, 2.0-4.0 parts of Bi2O3, 0.4-0.7 part of MnO, 1.5-3.5 parts of Sb2O3, 0.5-1.5 parts of Co2O3, 0.2-1.0 part of Cr2O3, and 1-5 parts of seed crystal doped materials. The seed crystal doped materials include ZnO, Nb2O5 and In2O3, wherein mass ratio of ZnO: Nb2O5: In2O3 is 90-95: 0.1-5: 0.1-5. The In<3+> and Nb<5+> composite donor-doped ZnO voltage-sensitive ceramic has characteristics of reducing ZnO grain resistivity and controlling ZnO lattice distortion to finally achieve low residual voltage of ZnO varistor, long aging life and strong pulse current withstand capacity.