47 results about "Mode field diameter" patented technology

A multicore optical fiber may include a common cladding comprising a radius R4 defining a glass portion of the optical fiber and having a cladding relative refractive index Δ4. At least two waveguides may extend through the common cladding. Each waveguide may include a core region, an inner cladding region, and a depressed cladding region. Each core region may include a maximum relative refractive index Δ1max. Each inner cladding region may include a relative refractive index Δ2. Each depressed cladding region may include a minimum relative refractive index Δ3min and a trench volume from 20-45%µm2 such that Δ1max>Δ2>Δ3min, and Δ4>Δ3min. A cable cutoff wavelength of each waveguide is ≤1150 nm. The co-propagating and counter-propagating inter-waveguide cross talk between each waveguide and a nearest waveguide is <-35 dB at 1310 nm and <-20 dB at 1550 nm for application lengths of 20 m. A mode field diameter of each waveguide is 8.2-9.0 µm at 1310 nm.

A polarization maintaining optical fiber (1) has: a core (11); an inner layer (12) that surrounds the core (11) without a gap; a pair of stress applying portions (13) disposed at positions sandwiching the core (11); and a cladding (14) that encloses the inner layer (12) and the pair of stress applying portions (13), a mode field diameter of light of a wavelength of 1.55 μm is 9.3 μm or less in a case where the light propagates in the core (11), a cutoff wavelength is 1.32 μm or more in a case where the optical fiber length is 0.25 m and the stress applying portions (13) are wound one turn around an axis having a radius of 2 mm in a manner that a slow axis of the stress applying portions (13) is perpendicular to a surface of the axis, and a product of an area of a cross section of the inner layer (12) perpendicular to a length direction and an average of relative refractive index differences of the inner layer (12) as a whole with respect to the cladding (14) is -36% μm 2 or more and 0% μm 2 or less.

The application belongs to the technical field of passive optical devices, and discloses a multiplexer / demultiplexer suitable for a multi-core optical fiber and a preparation method thereof. In the application, a small outer diameter optical fiber is fused at one end of a single-mode optical fiber. The cladding diameter of the small outer diameter optical fiber is smaller than the cladding diameter of the single-mode optical fiber, and the cladding diameter of the small outer diameter optical fiber is equal to the core spacing of the multi-core optical fiber to be matched. The mode field diameter of the small outer diameter optical fiber is consistent with the mode field diameter of each core of the multi-core optical fiber. The small outer diameter optical fiber is used as a transition optical fiber between the single-mode optical fiber and the multi-core optical fiber, high-precision matching between the single-mode optical fiber and the multi-core optical fiber is realized, the problems existing in the prior art preparation method can be avoided, and the application has the advantages of good scalability, simple preparation, high precision, and industrialized mass production.

A multi-core fiber coupler based on single-clad optical fibers (1), and a taper ratio design method therefor. Each single-clad optical fiber (1) comprises a fiber core (13), a cladding (12), and a coating layer (11), arranged in sequence from inside to outside. The multi-core fiber coupler based on single-clad optical fibers (1) comprises single-clad optical fibers (1) and a sleeve (2). Several single-clad optical fibers (1) are nested within the sleeve (2), and the total number of the single-clad optical fibers (1) is equal to the total number of fiber cores in a target multi-core optical fiber (3). One end of the sleeve (2) is tapered, and the other end is not tapered. A mode field diameter of each single-clad optical fiber (1) at the non-tapered end of the sleeve (2) matches a mode field diameter of a single fiber core of the target multi-core optical fiber (3). The single-clad optical fibers (1) and the multi-core fiber coupler have the advantages of low fabrication difficulty, low cost, and the capability of achieving low-loss connection with multi-core optical fibers and standard single-mode optical fibers.

A polarization-maintaining optical fiber (1) is provided with: a core (11); a pair of stress applying sections (12a, 12b) disposed at positions so as to sandwich the core (11); and a cladding (13) that encloses the core (11) and the pair of stress-applying sections (12a, 12b), the stress-applying sections (12a, 12b) having a torsion section (1A) in which the stress-applying sections (12a, 12b) are permanently spirally rotated around the core (11), the spiral torsion of the stress-applying sections (12a, 12b) per 47.1 mm in the torsion section (1A) being within one circle, and the polarization-maintaining optical fiber having a mode field diameter of 9.2 [mu] m or less at a wavelength of 1.31 [mu] m and a mode field diameter of 9.2 [mu] m or less at a wavelength of 47.1 [mu] m. When the optical fiber length is 2 m and the bending radius is 140 mm, the cutoff wavelength of the polarization-maintaining optical fiber is 1.15 [mu] m or more and less than 1.31 [mu] m.

The application discloses an optical fiber device, a preparation method of the optical fiber device and a coupling device, and belongs to the technical field of micro-nano photonics. The application sequentially arranges a mode field expansion area and a phase modulation area at an exit end of an optical fiber, uses the mode field expansion area to expand a beam mode field diameter, uses a substrate film matched with the mode field expansion area in refractive index and a micro-nano unit with high refractive index to form the phase modulation area, realizes a target phase distribution based on geometric sizes and / or a rotation angle of the micro-nano unit, and then performs phase modulation and wavefront shaping on the expanded beam, so as to output a target light field such as a focused beam, a collimated beam, a Bessel beam or a Bessel beam array. The optical fiber device can realize high coupling efficiency, high alignment tolerance and multi-functional wavefront regulation at the exit end of the optical fiber, can solve the mode field mismatch problem in optical fiber-chip coupling, can reduce system complexity and realize multi-functional integration.

A photonic crystal fiber (10) comprises: a core region (11) having a rare earth element added thereto; and a cladding region (12) including a plurality of refractive index reduction parts (13) provided around the core region (11). Each of the refractive index reduction parts (13) is formed of a glass rod having a refractive index lower than that of the cladding region (11) or a hole. The mode field diameter of the basic mode at a wavelength of 1.55 µm is not less than 16.4 µm.

The invention discloses a hollow-core optical fiber mode field diameter measuring unit and system. The hollow-core optical fiber mode field diameter measuring unit comprises a displacement table, a hollow rotating mechanism, a first swing arm, a rotating motor, a second swing arm and a detection mechanism. The hollow rotating mechanism is fixed on the displacement table; the displacement table is used for changing the spatial position of the hollow rotating mechanism; the hollow rotating mechanism is of a hollow annular structure, an annular rotating part is arranged on the outer side of the hollow rotating mechanism, one end of the first swing arm is connected with the annular rotating part, the other end of the first swing arm is connected with the rotating motor, the rotating end of the rotating motor is connected with the second swing arm, and the end of the second swing arm is connected with the detection mechanism. During measurement, the measured end part of the hollow-core optical fiber is arranged at the center of the hollow rotating mechanism, the hollow rotating mechanism controls the first swing arm to do circular motion around the end part of the hollow-core optical fiber, the rotating motor controls the second swing arm to do circular motion around the rotating end, and the detection mechanism forms a composite scanning track under the common driving of the hollow rotating mechanism and the rotating motor.

Embodiments of current disclosure include a multicore optical fiber including a radius RCC ranging from 126 μm to 180 μm, and core elements disposed within the common cladding. The common cladding may include an inner common cladding region, and an outer common cladding region surrounding the inner common cladding region and doped with TiO2. At least one core element may include a core region, a dedicated inner cladding region surrounding the core region, and a dedicated outer cladding region surrounding the dedicated inner cladding region. A mode field diameter at 1310 nm of the at least one core element may be greater than or equal to 8.6 μm. The at least one core element may be separated from a nearest-neighbor core element by a minimum separation distance DNN greater than or equal to 35 μm and less than or equal to 43 μm.

This invention relates to a single-mode optical fiber supporting fiber-to-chip interconnect applications, comprising a core layer and a cladding layer, wherein the core layer R1 has a radius of 4.2–6.2 μm, and Δ n The cladding thickness ranges from 0.25% to 0.4%, and from the inside out, it consists of an inner cladding, a first planarization layer, a first depressed cladding, a second planarization layer, a second depressed cladding, and an outer cladding. The radius of the inner cladding, R2, is 5.6–9 μm, and Δn2 decreases linearly. The radius of the first planarization layer, R3, is 8.1–9.2 μm, and Δn2 decreases linearly. n 3 is -0.05% to 0.05%, the radius of the first indented blanket R4 is 18.8 to 28.4 μm, Δ n 4 is -0.95% to -0.55%, the radius R5 of the second flattening layer is 24.2 to 29.2 μm, Δ n 5 is -0.05% to 0.05%, the radius of the second indented blanket R6 is 35 to 50 μm, Δ n The 6-value is -0.50% to -0.75%, and the outer cladding layer is a pure silica glass layer. This invention has a low cutoff wavelength, a large mode field diameter, and good bending performance in short-distance applications.

A waveguide structure (400), a silicon optical chip, a detection apparatus (1500), and a terminal device, used for reducing transmission loss caused by a TPA effect in waveguides under high optical power. The waveguide structure (400) comprises an edge coupler (EC) (4111), a first waveguide (4112), and a second waveguide (4113); the first waveguide (4112) is connected to a first output end of the EC (4111); the second waveguide (4113) is connected to a second output end of the EC (4111); an input end of the EC (4111) has a first mode field diameter; the first waveguide (4112) and the second waveguide (4113) each have a second mode field diameter; and the first mode field diameter is greater than the second mode field diameter. An input of the EC (4111) is a large mode field diameter, and outputs of the EC (4111) are two small mode field diameters. The EC (4111) can directly split an input optical signal into two waveguides, so that the optical power in each waveguide is reduced, high optical power density is not prone to occurring in each waveguide, and thus a TPA effect is not prone to occurring, thereby solving the problem of large transmission loss caused by the TPA effect in waveguides under high optical power density.

An apparatus includes a first photonic crystal fiber. The first photonic crystal fiber includes a first dispersion at a pump wavelength. The first photonic crystal fiber includes a zero dispersion. The pump wavelength is within 100 nm of the zero dispersion. The first dispersion is normal. The first photonic crystal fiber includes a first mode field diameter at the pump wavelength. The apparatus also includes a second photonic crystal fiber coupled to the first photonic crystal fiber and outputs a broadband spectrum. The second photonic crystal fiber includes a second dispersion at the pump wavelength. The second dispersion is anomalous. The second dispersion is negative, and the first dispersion is positive. The second photonic crystal fiber includes a second mode field diameter at the pump wavelength. The second mode field diameter is smaller than the first mode field diameter.

According to some embodiments disclosed herein, an optical device includes an optical source, a mode field adapter, and an optical output fiber. The optical source is configured to provide source light having a first mode field diameter at a wavelength of the source light. The mode field adapter includes a coreless optical fiber and a graded index optical fiber optically coupled in series with the optical source. The mode field adapter is configured to receive the source light and to provide output light having a second mode field diameter at the wavelength of the source light, and the first and second mode field diameters are different. The optical output fiber has the second mode field diameter at the wavelength. The mode field adapter is optically coupled between the optical source and the optical output fiber. The optical output fiber and the mode field adapter are joined by a splice.

The optical fiber laser device of the present application has a first optical fiber (30) composed of a polarization maintaining optical fiber, a second optical fiber (40), and a third optical fiber (50). The first optical fiber (30) has at least one first section (31) and at least two second sections (32) disposed alternately with the first section (31). Adjacent first sections (31) and second sections (32) are connected to each other in such a manner that the fast axis (31X1) of the first section (31) and the slow axis (32X2) of the second section (32) coincide at the connection site. The total length of the first section (31) is equal to the total length of the second section (32). The mode field diameter of the first optical fiber (30) is smaller than each of the mode field diameters of the second optical fiber (40) and the third optical fiber (50).

A polarization-maintaining optical fiber (1) is provided with a core (11), stress application sections (12a, 12b), and a cladding (13), the polarization-maintaining optical fiber having a mode field diameter of 9.2 [mu] m or less at a wavelength of 1.31 [mu] m, and a cutoff wavelength of 1.15 [mu] m or more and less than 1.31 [mu] m when the optical fiber length is 2 m and the bending radius is 140 mm, and satisfies at least one of (1) and (2). (1) The macrobend loss of the polarization maintaining fiber at a wavelength of 1.31 [mu] m is 0.76 dB / 1 turn or less when the bending radius is 7.5 mm and the fiber length is twisted for one turn per 47.1 mm. (2) The macrobend loss of the polarization maintaining fiber at a wavelength of 1.31 [mu] m is 0.11 dB / 1 turn or less when the bending radius is 10 mm and the fiber length is twisted for one turn per 62.8 mm.

This invention discloses a coupling structure and method for an anti-resonant hollow fiber and a single-mode fiber, belonging to the field of fiber coupling technology. The technical solution is as follows: a coupling structure for an anti-resonant hollow fiber and a single-mode fiber, characterized by comprising a broadband light source, a first single-mode fiber, an anti-resonant hollow fiber, a tapered coreless fiber, a tapered single-mode fiber, a second single-mode fiber, and a spectrometer. The beneficial effect of this invention is that by adjusting the parameters of the tapered coreless fiber, the light emitted from the anti-resonant hollow fiber is focused into the tapered single-mode fiber, thereby achieving mode field diameter matching between the single-mode fiber and the anti-resonant hollow fiber. Simulation and experimental results show that, compared to the traditional coupling of a tapered single-mode fiber and an anti-resonant hollow fiber, fusing a tapered coreless fiber at the tip of the tapered single-mode fiber significantly improves the coupling efficiency.

A power splitter may include a single-core optical fiber, a beam-splitting optical fiber, and a multicore optical fiber. The beam-splitting optical fiber may include a polygonal core configured to output a multimode interference beam pattern including a plurality of beam spots, an input end coupled to the single-core optical fiber, and an output end coupled to the multicore optical fiber. In embodiments, a difference between a mode field diameter of the cores of the multicore optical fiber and a mode field diameter of the core of the single-core optical fiber may be less than or equal to 50%. In embodiments, when the power splitter is in operation, a difference between a distance between neighboring beam spots of the multimode interference beam pattern output by the beam-splitting optical fiber and a core pitch of the cores of the multicore optical fiber may be less than or equal to 10%.

A single mode optical fiber is provided that includes a core region having an outer radius r1 and a maximum relative refractive index Δ1max. The single mode optical fiber further includes a cladding region surrounding the core region, the cladding region includes a depressed-index cladding region, a relative refractive index Δ3 of the depressed-index cladding region increasing with increased radial position. The single mode optical fiber has a bend loss at 1550 nm for a 15 mm diameter mandrel of less than about 0.75 dB / turn, a bend loss at 1550 nm for a 20 mm diameter mandrel of less than about 0.2 dB / turn, and a bend loss at 1550 nm for a 30 mm diameter mandrel of less than 0.005 dB / turn. Additionally, the single mode optical fiber has a mode field diameter of 9.0 microns or greater at 1310 nm wavelength.

According to some embodiments disclosed herein, an optical device includes an optical source, a mode field adapter, and an optical output fiber. The optical source is configured to provide source light having a first mode field diameter at a wavelength of the source light. The mode field adapter includes a coreless optical fiber and a graded index optical fiber optically coupled in series with the optical source. The mode field adapter is configured to receive the source light and to provide output light having a second mode field diameter at the wavelength of the source light, and the first and second mode field diameters are different. The optical output fiber has the second mode field diameter at the wavelength. The mode field adapter is optically coupled between the optical source and the optical output fiber. The optical output fiber and the mode field adapter are joined by a splice.

The application discloses a thin-film lithium niobate hetero-integrated double-layer mode spot converter, which comprises a lower lithium niobate waveguide module and an upper silicon nitride waveguide module, the lower lithium niobate waveguide module and the upper silicon nitride waveguide module are positioned by a silicon oxynitride cladding layer, the upper silicon nitride waveguide module is suspended in the silicon oxynitride cladding layer and the suspension height is greater than the thickness of the lower lithium niobate waveguide module, and the silicon oxynitride cladding layer is arranged above a silicon oxide substrate; the lower lithium niobate waveguide module is designed by gradually changing the waveguide width, thereby realizing efficient conversion from a fiber mode to a lithium niobate ridge waveguide base mode; and the upper silicon nitride waveguide module realizes low-loss mode conversion between lithium niobate-silicon nitride hetero waveguides by a three-dimensional reverse taper coupling structure. The double-layer mode spot converter realizes optical field coupling between hetero materials by a vertical stacking structure of a thin-film lithium niobate ridge waveguide and a suspended silicon nitride strip waveguide, and in combination with a lithium niobate ridge waveguide width modulation technology, continuous regulation and control of a mode field diameter can be effectively realized.

A fiber laser device includes a first optical fiber, a second optical fiber, and a third optical fiber configured by polarization maintaining fibers. The first optical fiber includes at least one first part and at least two second parts alternatively disposed with the first part. The first part and the second part adjacent to each other are connected to each other such that a fast axis of the first part coincides with a slow axis of the second part at a connection point. A total length of the first part is equal to a total length of the second parts. A mode field diameter of the first optical fiber is smaller than each of a mode field diameter of the second optical fiber and a mode field diameter of the third optical fiber.

The mode field diameter acquisition device according to the present disclosure is a device for acquiring a mode field diameter of each spatial mode of an optical fiber having a core, through which a plurality of spatial modes can propagate, from a near field pattern, and includes a mode field diameter acquisition unit configured to acquire a mode field diameter of a freely-selected spatial mode using a near field pattern of the spatial mode, and a mathematical expression based on a variational expression of a propagation constant of the spatial mode.

An optical fiber (10) comprises: a core (11) which is doped with a rare earth element; and a cladding (12) which has a refractive index that is lower than the core (11) by a relative refractive index difference Δ. The radius a of the core (11) and the relative refractive index difference Δ have values such that the mode field diameter of not less than 16.4 μm is obtained at a wavelength of 1.55 μm.

This invention relates to the field of laser measurement instrument technology and discloses an automatic loss detection method for fiber optic connectors based on optical signal attenuation analysis. The method includes: acquiring the backscattered light power sequence of the fiber optic link under test; calculating the logarithmic rate of change of power behind the connector feature point to generate a logarithmic power attenuation rate sequence; processing the sequence through a sliding window to calculate the spatial autocorrelation coefficient and determine a stationarity discrimination index characterizing the evolution trend of mode distribution; identifying the spatial location where the index enters the noise baseline range and establishing the mode equilibrium inflection point; and based on the power evolution relationship between the inflection point and the feature point, stripping the power fluctuation component caused by mode field diameter mismatch and calculating the intrinsic insertion loss. This invention achieves deep decoupling of energy transient fluctuations caused by mode reconstruction and interface intrinsic loss in the spatial dimension, eliminating pseudo-loss interference generated by heterogeneous fiber interconnects.

The invention discloses a hollow-core optical fiber mode field diameter testing device and method based on a far field method, and relates to the technical field of hollow-core optical fiber testing, a control unit is mainly responsible for work and time sequence of all devices in the whole device, and a light source is an injection light source when a hollow-core optical fiber to be tested. The hollow-core optical fiber automatic coupling unit can automatically couple light emitted by the light source into a to-be-tested hollow-core optical fiber, the multifunctional displacement table can move in the X direction, the Y direction and the Z direction at the tested end of the to-be-tested hollow-core optical fiber, and the vertical rotating platform is a moving device for scanning the power of the end face of the to-be-tested hollow-core optical fiber. The power detection unit collects end face power of a to-be-detected hollow-core optical fiber, the hollow-core optical fiber end face image collection unit collects a detected end face image of the to-be-detected hollow-core optical fiber, and the signal analysis unit analyzes and processes collected power signals. According to the invention, the optical fiber end face image observation unit is matched with the multifunctional displacement table, so that automatic, efficient and multi-dimensional hollow-core optical fiber mode field diameter testing can be realized.

The present disclosure relates to an optical edge coupler or spot-size converter (SSC) that includes multiple juxtaposed layers of auxiliary waveguides with underlying silicon-on-insulator (SOI) waveguides. In one embodiment, the SSC includes two waveguide layers, each having four auxiliary waveguides, including two inner auxiliary waveguides interposed between two outer auxiliary waveguides. The waveguide layers collectively include at least two sections. In the first section, each auxiliary waveguide diverges in the direction of light propagation. In the second section, each outer auxiliary waveguide converges toward each other. The SOI waveguides partially overlap the first section and completely overlap and extend beyond the second section. The SSC facilitates coupling of light from a flat-cleaved standard single-mode fiber with a mode field diameter of 10.4 μm at 1550 nm into the SOI waveguide, which has low loss and flat-band response at C-band and L-band communication wavelengths.

A power splitter may include a single-core optical fiber, a beam-splitting optical fiber, and a multicore optical fiber. The beam-splitting optical fiber may include a polygonal core configured to output a multimode interference beam pattern including a plurality of beam spots, an input end coupled to the single-core optical fiber, and an output end coupled to the multicore optical fiber. In embodiments, a difference between a mode field diameter of the cores of the multicore optical fiber and a mode field diameter of the core of the single-core optical fiber may be less than or equal to 50%. In embodiments, when the power splitter is in operation, a difference between a distance between neighboring beam spots of the multimode interference beam pattern output by the beam-splitting optical fiber and a core pitch of the cores of the multicore optical fiber may be less than or equal to 10%.

The invention discloses an optical fiber mode multiplexing quasi-homochromatic marginal light suppression super-resolution photoetching system. The system aims to solve the problem of nonlinear dispersion of femtosecond laser in optical fiber transmission and the problem of poor stability of annular suppression light spots generated by a traditional spatial light path. The core lies in three modules: firstly, a fiber-grating-fiber dispersion compensation module (a large-mode-field-diameter photonic crystal fiber is combined with a grating pair) is adopted, so that broadening of femtosecond pulses is effectively inhibited, and high-peak power required by inscribing is ensured; the optical fiber generation of an incoherent Hermite-Gaussian mode is realized, annular suppression and Gaussian excitation light spots (collectively called PPI light spots) with stable intensity distribution are synthesized, and the anti-interference capability of the system is remarkably improved. And parallel direct writing is realized through the multi-channel optical fiber array and the high-speed scanning module. According to the invention, the PPI light spot array with low dispersion and high stability is generated by using the optical fiber, the expansibility is good, and high-precision and high-flux three-dimensional super-resolution photoetching processing can be realized.

This invention belongs to the field of fiber optic connector technology and discloses a photonic crystal fiber connector and its fabrication method. The photonic crystal fiber connector provided by this invention includes a photonic crystal fiber, a bridge fiber, and a connector assembly. A light-transmitting positioning plate is embedded in the ferrule of the connector assembly. The photonic crystal fiber and the bridge fiber are respectively fixed on both sides of the light-transmitting positioning plate. The mode field diameter of the end of the bridge fiber closest to the light-transmitting positioning plate is the same as the mode field diameter of the photonic crystal fiber. The end of the bridge fiber furthest from the light-transmitting positioning plate serves as the mating end face with other fiber optic connectors, and the mode field diameter of this end is the same as the mode field diameter of the other fiber optic connectors to be mated with. In fabricating the photonic crystal fiber connector, this invention only grinds the end of the bridge fiber furthest from the light-transmitting positioning plate. This invention can effectively avoid the blockage, damage, or contamination of the micropore structure of the photonic crystal fiber.

The present invention relates to an optical fiber (200) having a core (202) extending along a central axis (206) and a cladding (204) concentrically surrounding the core (202). The core (202) has at least 83-mole percent (mol %) of Silicon dioxide (SiO2) and at most 17-mole percent (mol %) of an up-dopant and, the cladding (204) has at least 99-mole percent (mol %) of Silicon dioxide (SiO2). Further, the optical fiber (200) has (i) an effective area of greater than or equal to 100 μm2, (ii) a mode field diameter (MFD) in a range of 11 μm to 15 μm, and (iii) a chromatic dispersion of less than or equal to 23.5 picoseconds (ps / (Km·nm) at a wavelength of 1550 nm.