18 results about "Zero-dispersion wavelength" patented technology

A low-loss bend-resistant single-mode optical fiber (10), comprising, from the center toward the outside, a core layer (11), a first inner cladding layer (12), a second inner cladding layer (13), a depressed cladding layer (14), and an outer cladding layer (15) which are sequentially arranged. The outer radius of the first inner cladding layer (12) is R2, the width R2-R1 of the first inner cladding layer (12) ranges from 1 μm to 4 μm, and a relative refractive index difference Δ2 between the first inner cladding layer (12) and the outer cladding layer (15) ranges from -0.2% to 0%; the outer radius of the second inner cladding layer (13) is R3, the width R3-R2 of the second inner cladding layer (13) ranges from 1 μm to 4 μm, and a relative refractive index difference Δ3 between the second inner cladding layer (13) and the outer cladding layer (15) ranges from -0.1% to 0.1%; and the first inner cladding layer (12) and the second inner cladding layer (13) which have different refractive indices are arranged between the core layer (11) and the depressed cladding layer (14). By adjusting the difference value of a refractive index difference between the first inner cladding layer (12) and the second inner cladding layer (13), a zero-dispersion wavelength shifts towards a long wavelength direction, and the slope of the zero-dispersion wavelength is reduced, achieving compatibility with G.652 dispersion standard requirements.

This optical fiber comprises a core that contains germanium, and a cladding that surrounds the core. The zero-dispersion wavelength of the optical fiber is 1307-1317 nm. The standard deviation of the zero-dispersion wavelength is 1.6 nm or less.

The discovery of a clear correlation between the Anderson localization length and the dispersion properties of highly localized TALOF modes allowed us to demonstrate that the zero dispersion wavelength can be tuned over more than 300 nm within the same fiber by selected excitation of specific modes. This enabled apparatus and methods for generating tunable, multi-octave-spanning supercontinuum (SC) spectra in a bandwidth from 460 nm to 1750 nm. Associated applications are also presented.

Provided is a reception device comprising: a reception unit that receives a plurality of optical signals having different wavelengths and transmitted from one or more opposing devices connected via an optical transmission path; and a signal processing unit that calculates, for each of the received optical signals on the basis of the frequency spectrum thereof, a notch frequency at which a notch appears in the frequency domain excluding harmonics of the frequency of the received optical signal, and uses the plurality of calculated notch frequencies and chirp values corresponding to the wavelengths of the respective plurality of optical signals to estimate one or more zero dispersion wavelengths in the optical transmission path.　

Provided is a reception device comprising: a reception unit that receives a plurality of optical signals having different wavelengths transmitted from one or more partner devices connected via an optical transmission path; and a signal processing unit that, on the basis of the frequency spectrum of each of the plurality of received optical signals, calculates, for each received optical signal, a notch frequency in which a notch appears at a frequency excluding a multiple of the frequency of the received optical signal, and estimates one or more zero-dispersion wavelengths in the optical transmission path by using the calculated plurality of notch frequencies and a chirp value corresponding to the wavelength of each of the plurality of optical signals.　

A supercontinuum source including a pump light source arranged to emit pump light and a nonlinear fiber having a core arranged to receive the pump light. The supercontinuum includes infrared wavelengths generated in the nonlinear fiber from the pump light. The nonlinear fiber has a dispersion profile including a zero dispersion wavelength, a positive peak value at a peak wavelength longer than the zero dispersion wavelength, a minimum value of dispersion at a minimum wavelength longer than the peak wavelength. The pump light is arranged to include substantial energy at one or more preferred pump wavelengths which are 10 nm longer than the zero dispersion wavelength or more. Also, a supercontinuum pump source including a nonlinear fiber having a core including a fluoride glass and having a core diameter smaller than 7 μm, where the fiber has a numerical aperture of more than 0.26.

The present invention provides an optical fiber with improved optical properties such as zero dispersion wavelength by suppressing the volatilization of dopant materials such as germanium dioxide and optimizing the refractive index distribution by adjusting the setting position of the core portion burner for deposition in a larger optical fiber preform. An optical fiber preform includes a core portion with a relatively high refractive index and a clad portion with a relatively low refractive index, wherein a position having a value of 45% of a refractive index difference between a center of the core portion and the clad portion is a boundary rcore (mm) between the core portion and the clad portion; and when a radius position r at which a refractive index difference with the clad portion being a maximum value is rside (mm), rside / rcore is 0.745 to 1.

A hollow-core photonic crystal fiber (HC-PCF) assembly for converting input radiation into broadband radiation, the hollow-core fiber assembly comprising: a microstructured fiber having a hollow core that extends along a length of the fiber from an input end configured to receive the input radiation to an output end configured to output the broadband radiation, wherein the hollow core of the fiber is configured to contain a medium; and a density control system configured to control a density profile of the medium along at least a portion of the length of the fiber to establish a desired zero-dispersion wavelength profile along at least a portion of the length of the fiber.

An optical fiber has a silica-based core region having an outer radius r1 of about 4.0 [mu] m to about 4.6 [mu] m and a core volume of about 4.5% [delta]-[mu] 2 to about 5.5% [delta]-[mu] 2. The optical fiber also includes a depressed index cladding region and an outer cladding region. The recessed refractive index cladding region has an inner radius r2 such that r1 / r2 is greater than about 0.4 but less than about 0.6, and has a trench volume of between about-50% [Delta]-[mu] 2 and about-20% [Delta]-[mu] 2. The optical fiber has: a mode field diameter at 1310 nm from about 8.8 microns to about 9.4 microns; a 2 m optical cable cut-off, from about 1120 nm to about 1260 nm; a bending loss at 1310 nm, determined by a mandrel winding test performed using a mandrel having a diameter of 15 mm, of less than 1.0 dB / turn; and a zero dispersion wavelength between 1300 nm and 1324 nm.

Provided is a communication device that performs wavelength division multiplexing communication with a counterpart device that is a communication partner. The communication device comprises: a wavelength arrangement determination unit that determines a plurality of wavelengths to be used for communication with the counterpart device on the basis of a wavelength arrangement determined so as not to overlap a frequency position of idler light generated by four-wave mixing and an estimate value of the zero dispersion wavelength of a communication path connected to the counterpart device; a plurality of transmitters that transmit the light of the plurality of wavelengths determined by the wavelength arrangement determination unit; and a multiplexing unit that wavelength-multiplexes and outputs the light of the plurality of wavelengths outputted from each of the plurality of transmitters.　

An optical fiber including a core region having an outer radius r1 in a range from 4.0 μm to 8.0 μm and a relative refractive index profile Δ1 with a maximum relative refractive index Δ1max in a range from 0.20% to 0.50%, a cladding region comprising a trench cladding region having a minimum relative refractive index Δ3 min greater than −0.60% and less than −0.10%, and a trench volume greater than 30%-μm2 and an outer cladding region having a relative refractive index Δ4 in a range from −0.10% to 0.10%. The optical fiber also including a primary coating and a secondary coating. The optical fiber has a mode field diameter at 1310 nm of greater than 8.8 microns, a cable cutoff wavelength of less than 1260 nm, a zero dispersion wavelength between 1300 nm and 1324 nm, and low macrobend loss at 1550 nm.

To provide a multicore optical fiber that suppresses attenuation, increases transmission capacity, and achieves low crosstalk.SOLUTION: In a multicore optical fiber including a common cladding having a diameter of 120 μm to 130 μm and a plurality of core portions arranged in the common cladding, each core portion includes a low-refractive-index cladding region forming a low-refractive-index cladding trench in a relative refractive index profile. The mode field diameter of each core portion is 8.2 μm or more and 9.5 μm or less at a wavelength of 1310 nm, and a zero-dispersion wavelength is 1300 nm or more and 1324 nm or less. Center axes of the plurality of core portions are spaced apart from each other by a minimum separation distance of 35 μm or more, and crosstalk between each core portion and the closest core portion among the core portions is -30 dB or less.SELECTED DRAWING: Figure 1

The MCF of the present invention can ensure sufficient manufacturing tolerance, has excellent mass producibility, and can also suppress the deterioration of connection loss. The MCF has four cores extending along the central axis and a common cladding. Each core has an adjacent relationship with two of the remaining cores, and the central interval Λ between the cores in the adjacent relationship is Λ nominal -0.9 μm or more and Λ nominal +0.9 μm or less. The outer diameter of the common cladding is 124 μm or more and 126 μm or less. The MFD, λ cc and d coat satisfy a specified relationship. The MFD has a value of 8.6 μm or more and 9.2 μm or less as the MFD reference value, and is -0.4 μm or more and +0.4 μm or less of the MFD reference value. The zero-dispersion wavelength has a value of 1312 nm or more and 1340 nm or less as the wavelength reference value, and is -12 nm or more and +12 nm or less of the wavelength reference value. The dispersion slope of the zero-dispersion wavelength is 0.092 ps / (nm 2 ·km) or less, λ cc is 1260 nm or less, and satisfies the specified structural conditions and optical conditions.

An optical fiber may include a core region and a cladding region surrounding the core region. The cladding region may include an inner cladding region surrounding the core region, a depressed-index cladding region surrounding the inner cladding region, and an outer cladding region surrounding the depressed-index cladding region. The inner cladding region may include a thickness greater than or equal to 1 μm. The depressed-index cladding region may include a first region and a second region, wherein a relative refractive index of the depressed-index cladding region may decrease monotonically with increasing radius in the first region, and wherein the relative refractive index of the depressed-index cladding region may be substantially constant in the second region. The optical fiber may achieve low microbend loss with large mode field diameter, while also maintaining low macrobend loss, low cable cutoff, and / or a zero dispersion wavelength between 1300 nm and 1324 nm.

Provided is an MCF or the like having a configuration that is excellent in mass productivity, and that can suppress an increase in connection cost and connection loss. The MCF has a core group including 12 or 16 cores, a common cladding layer, and a resin covering portion. The cores are arranged in a line-symmetrical position in a state in which cores in an adjacent relationship with respect to any core do not have an adjacent relationship with each other. The covering outer diameter is 235 μm or more and 265 μm or less, and the nominal value of the diameter CD with respect to the common cladding layer is 195 μm or less, converging to a value range of CD nominal ±1 μm, the MFD at a wavelength of 1310 nm converges to a value range of the prescribed MDF reference value ±0.4 μm with respect to a prescribed MDF reference value of 8.2 μm or more and 9.2 μm or less, and the cable cutoff wavelength λ cc is 1260 nm or less or 1360 nm or less. The zero-dispersion wavelength of each core converges to a value range of a wavelength reference value ±12 nm with respect to a wavelength reference value of 1312 nm or more and 1340 nm or less, and the dispersion slope at the zero-dispersion wavelength is 0.092 ps / (nm 2 ·km) or less. The shortest distance from the covering-cladding layer interface to the center of each core, the configuration, and the optical characteristics satisfy prescribed conditions.

To transmit a plurality of wavelength-multiplexed signal lights in a wavelength band including a wavelength at which wavelength dispersion becomes zero.SOLUTION: The control apparatus includes an acquisition unit configured to acquire a signal-to-noise ratio of each of the plurality of signal lights from the optical reception apparatus, and a calculation unit configured to calculate the signal-to-noise ratio of the signal light based on a level of the signal light and a zero dispersion wavelength of an optical transmission path. And control means for determining a target value of a level of each of the plurality of signal lights output to the optical transmission line by the optical transmission device, and controlling the optical transmission device such that the level of each of the plurality of signal lights output to the optical transmission line by the optical transmission device becomes the target value, wherein the control means sets a wavelength of a signal light at which a signal-to-noise ratio in the optical reception device is lowest in a state where the optical transmission device is controlled such that the level of each of the plurality of signal lights output to the optical transmission line by the optical transmission device is the same, as a zero dispersion wavelength in a closed form.SELECTED DRAWING: Figure 2

Provided is a communication device comprising: a reception unit that receives information pertaining to a communication device that performs communication; and a calculation unit that calculates, on the basis of transmission path information pertaining to a zero dispersion wavelength for each path connecting a plurality of devices and the information pertaining to the communication device received by the reception unit, a zero dispersion wavelength of a communication path formed by a combination of a plurality of paths connected via one or more distribution devices that switch connection paths between communication devices that perform communication.　

A supercontinuum source including a pump light source arranged to emit pump light and a nonlinear fiber having a core arranged to receive the pump light. The supercontinuum includes infrared wavelengths generated in the nonlinear fiber from the pump light. The nonlinear fiber has a dispersion profile including a zero dispersion wavelength, a positive peak value at a peak wavelength longer than the zero dispersion wavelength, a minimum value of dispersion at a minimum wavelength longer than the peak wavelength. The pump light is arranged to include substantial energy at one or more preferred pump wavelengths which are 10 nm longer than the zero dispersion wavelength or more. Also, a supercontinuum pump source including a nonlinear fiber having a core including a fluoride glass and having a core diameter smaller than 7 μm, where the fiber has a numerical aperture of more than 0.26.