Abstract:
An optical waveguide having a cladding layer formed of high-purity glass, or a cladding layer formed of high-purity isotope-proportion modified glass, and with a core of high-purity isotope-proportion-modified glass with the index of refraction of the core glass greater than the index of refraction, of the cladding glass, said high-purity isotope-proportion-modified core material having a Si-29-isotope proportion at most 4.447 % Si-29 (atom/atom) of all silicon atoms in said core, or at least 4.90% of Si-29 (atom/atom) atoms in said core, or having a Ge-73 isotope proportion of at most 7.2% Ge-73 (atom/atom) of all germanium atoms in said core, or at least 8.18% of Ge-73 (atom/atom) of Germanium atoms in said core region.
Abstract:
According to some embodiments a single mode fiber includes: a germania doped central core region having outer radius r 1 and relative refractive index Δ 1 ; and a cladding region comprising (i) a first inner cladding region having an outer radius r 2 > 6 microns and relative refractive index Δ 2 and 0.3≤r 1 /r 2 ≤0.85; and (ii) a second inner cladding region having an outer radius r 3 > 9 microns and comprising a minimum relative refractive index Δ 3 , wherein said second inner cladding region has at least one region with a relative refractive index delta that becomes more negative with increasing radius; and (iii) an outer cladding region surrounding the inner cladding region and comprising relative refractive index Δ 4 , wherein Δ 1 > Δ 2 > Δ 3 , Δ 3 4 .
Abstract:
An optical waveguide fiber having a high threshold for stimulated Brillouin scattering. The optical fiber preferably has large optical effective area, and further preferably has a low zero dispersion wavelength.
Abstract:
A dispersion compensating optical fiber for use in a high data rate telecommunications span or link. The dispersion compensating optical fiber in accordance with the invention provides excellent compensation of total dispersion over a range of wavelengths (e.g., 1527-1567 nm), thus minimizing signal distortion in wavelength division multiplexed systems. The dispersion compensating fiber has a refractive index profile with a central core segment having an inner peak with a i%, an outer peak with 1%, and a trough with a t% less than both i% and 1%, a moat segment with a 2%, and a ring segment with a 3%. Preferably, t% and 3% are greater than 2%. Also disclosed is an optical transmission span having residual dispersion less than +/-25 ps/km for 100 km of transmission fiber over a wavelength band of 1527-1567 nm.
Abstract:
A half-dispersion-shifted single mode optical transmission fiber (HDSF) (78, 80; 68, 120) has a core and a cladding. The core comprises an inner core (70, 82; 60, 122) with a first refractive-index difference and a first glass layer (72, 84; 64, 126) surrounding the inner core and having a second refractive-index difference. The HDSF fiber has a peak refractive index difference of less than or equal to about 0.0140, a zero-dispersion wavelength greater than 1450 nm and lower than 1500 nm, a dispersion value of between about 6 and 11 ps/nm/km at an operating wavelength of about 1560 nm and an effective area of at least 60 mu m . The cabled HDSF fiber has cutoff wavelength of less than about 1500 nm. An optical transmission line (14; 94) comprises a first span (16, 96) including at least one single-mode fiber having a negative dispersion at an operating wavelength and a second span (18) coupling to the first span, the second span having at least one HDSF fiber, the positive dispersion of the second span compensating the negative dispersion of the first span such that the cumulative dispersion across the first and second spans is approximately zero.
Abstract:
A lower-dispersion optical fiber achieving both low wavelength dispersion in the usable wavelength region and enlarged effective core cross-section. The outer peripheral face of a center core (1) of the lower dispersion optical fiber is covered with a first side core (2) the outer peripheral face of the first side core (2) is covered with a second side core (3), and the outer peripheral face of the second side core (3) is covered with a clad (5). If the maximum refractive index of the center core (1) is n1, the minimum refractive index of the first side core (2) is n2, the maximum refractive index of the second side core (3) is n3, and the refractive index of the clad (5) is nc, a relation n1 > n3 > nc > n2 is satisfied. The relative refractive-index differences DELTA 1, DELTA 2, and DELTA 3 of the maximum refractive index of the center core (1), and the minimum refractive index of the first side core (2) to tose of the clad (5) are, respectively, in the ranges of 0.4 % ≤ DELTA 1 ≤ 0.7 %, -0.30 % ≤ DELTA 2 ≤ -0.05 %, and 0.2 % ≤ DELTA 3.
Abstract:
A negative total dispersion waveguide fiber having low attenuation and compresses the launched signal pulse when the laser is positively chirped. The laser is provided at optimum bias, which results in positive chirp, but no dispersion penalty is incurred in the link. The waveguide fiber is used a dispersion compensating fiber in a high performance multiplexed telecommunications link. Curve (96) in figure 8 representative of a link comprising fiber having negative dispersion waveguide fibers. Curve (98) is representative of a link comprising fiber having negative dispersion at 1550 nm in accordance with the invention. Curve (100) is representative of a link comprising fiber in accordance with the invention and a laser source that is even more positively chirped thanthe laser to generate curve (98).
Abstract:
Disclosed is a single mode optical waveguide fiber having a relatively large effective area and good bend resistance. The waveguide fiber is characterized by a segmented core having a central segment (30) and at least one annular segment (32, 34, 36) surrounding the central segment. At least one segment has a negative relative refractive index where the reference refractive index is taken as the index of the cladding. The total dispersion of the fiber is positive for wavelengths above about 1500 nm, dispersion slope is typically less than about 0.08 ps/nm -km, and induced attenuation under pin array bend testing is typically less than 5 dB/km.
Abstract:
A pulse-reshaping optical fiber having a core with refractive index nc surrounded by a cladding layer, the diameter of the core changing monotonically along the length of the fiber. The core includes a central region having a maximum refractive index n1 and a moat region disposed radially adjacent to the central region. The moat region has a minimum refractive index n2 which is sufficiently low that the index delta DELTA 2 of the moat region with respect to nc is not greater than 0.1 %. The moat region affects the change in dispersion with respect to fiber cladding diameter, as well as providing the pulse-reshaping fiber with low dispersion versus wavelength slope. The pulse-reshaping fiber is particularly useful in association with optical transmission systems where high transmission rates and narrow pulse widths are desired, including components such as high pulse rate wavelentgh-division-multiplexers (WDMs) and optical regenerators.