Abstract: A multimode optical fiber includes a central core having a radius (r1) and an alpha-index profile. The multimode optical fiber further includes a depressed trench, which surrounds the central core, that has a width (wt) and a refractive index difference (?nt) with an outer optical cladding. Typically, the central core's diameter is between about 47 and 53 microns, and the depressed trench's width (wt) is between 0.5 micron and 2 microns. The depressed trench's refractive index difference (?nt) with the outer optical cladding is typically between ?4×10?3 and ?1×10?3.

Abstract: A multimode optical fiber comprises a central core having an alpha profile, a depressed cladding having a portion in continuity with the alpha profile of the central core and a stepped portion, and an outer cladding. The alpha profile is obtained by co-doping at least two dopants. The variation in concentration of each dopant and its derivative in relation to the fiber radius are continuous. A multimode fiber for Ethernet optical system with an improved bandwidth is thus obtained.

Abstract: A method of classifying a graded-index multimode optical fiber includes taking a series of individual measurements at a single wavelength, and using the measurements to characterize the departure of the multimode optical fiber's actual index profile from the corresponding nominal index profile. The measurements, coupled with intermodal dispersion or EMB measurement, may be used to predict the approximate transmission properties of the optical fiber at wavelengths other than the measurement wavelength.

Abstract: Disclosed is an optical system including a polychromatic optical source emitting multiple transverse modes, an optical link having at least one portion of multimode optical fiber, and an optical device positioned between the optical source and the input of the multimode optical fiber. The optical device can modify the distribution of the energy coupling of the transverse modes emitted by the source in the propagation modes of the multimode optical fiber. The optical system makes it possible to use low-cost transverse multimode optical sources for producing high-bandwidth Ethernet transmission networks having excellent performance.

Abstract: An optical transmission fiber comprises a central core having an index difference ?n1 with an outer optical cladding; a first inner cladding having an index difference ?n2 with the outer cladding; and a second buried inner cladding having an index difference ?n3 with the outer cladding of less than ?3.10?3. The second buried inner cladding moreover contains Germanium in a weight concentration of between 0.5% and 7%. The fiber shows reduced bending and microbending losses whilst exhibiting the optical performances of a standard single-mode fiber (SSMF).

Abstract: A multimode optical fiber has an equivalent modal dispersion value (DMDinner&outer) of less than 0.11 ps/m for (??max×D)>0.07 ps/m as measured on a modified DMD graph. The modified DMD graph accounts for chromatic dispersion to ensure that the multimode optical fiber has a calculated effective bandwidth EBc greater than 6000 MHz-km when used with multimode transverse sources.

Abstract: The present wavelength multiplexed optical system includes a multimode optical fiber that transmits wavelength multiplexed optical signals and a plurality of multimode modal dispersion compensation optical fibers. Each modal dispersion compensation optical fiber can transmit one of the multiplex wavelengths, and each modal dispersion compensation optical fiber has an optimized index profile such that the modal dispersion for the transmitted wavelength is approximately inversely equal to the modal dispersion induced in the multimode optical fiber. The wavelength multiplexed optical system facilitates an increased bitrate without reducing bandwidth.

Abstract: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Abstract: An optical transmission fiber includes a central core having an index difference ?n1 with an outer optical cladding; a first inner cladding having an index difference ?n2 with the outer cladding; and a second buried inner cladding having an index difference ?n3 with the outer cladding of less than ?3.10?3. The second buried inner cladding moreover contains Germanium in a weight concentration of between 0.5% and 7%. The fiber shows reduced bending and microbending losses whilst exhibiting the optical performances of a standard single-mode fiber (SSMF).

Abstract: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Abstract: A polarized lightwave reflectometry method including the steps of sending at least two polarized light signals into the optical fiber to be tested, the signals presenting a determined angular offset relative to each other so that the polarization mode dispersion coefficient remains independent of any rotation of polarization in the optical fiber under test; extracting a scalar parameter of the relative noise type for each trace obtained by back-scattering of the light signal; and estimating the polarization mode dispersion coefficient by a function having a single scalar input, which function is of the type based on exponentials and has the form exp (a+bP+cP?1).

Abstract: Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Abstract: An optical transmission fiber comprises a central core having an index difference ?n1 with an outer optical cladding; a first inner cladding having an index difference ?n2 with the outer cladding; and a second buried inner cladding having an index difference ?n3 with the outer cladding of less than ?3.10?3. The second buried inner cladding moreover contains Germaniumn in a weight concentration of between 0.5% and 7%. The fiber shows reduced bending and microbending losses whilst exhibiting the optical performances of a standard single-mode fiber (SSMF).

Abstract: A polarized lightwave reflectometry method including the steps of sending at least two polarized light signals into the optical fiber to be tested, the signals presenting a determined angular offset relative to each other so that the polarization mode dispersion coefficient remains independent of any rotation of polarization in the optical fiber under test; extracting a scalar parameter of the relative noise type for each trace obtained by back-scattering of the light signal; and estimating the polarization mode dispersion coefficient by a function having a single scalar input, which function is of the type based on exponentials and has the form exp (a+bP+cP?1).

Abstract: A polarized lightwave reflectometry method including the steps of sending at least two polarized light signals into the optical fiber to be tested, the signals presenting a determined angular offset relative to each other so that the polarization mode dispersion coefficient remains independent of any rotation of polarization in the optical fiber under test; extracting a scalar parameter of the relative noise type for each trace obtained by back-scattering of the light signal; and estimating the polarization mode dispersion coefficient by a function having a single scalar input, which function is of the type based on exponentials and has the form exp (a+bP+cP?1).

Abstract: The invention proposes a polarized lightwave reflectometry method which is more accurate and which can be considered as genuinely quantitative, at least over a given range of polarization mode dispersions.

Abstract: Natural or synthetic silica is deposited on a preform set into rotation in front of a plasma torch which moves back and forth substantially parallel to a longitudinal direction of the preform, a first feed duct feeds the plasma with grains of natural or synthetic silica while a second feed duct feeds the plasma with a fluorine or chlorine compound, preferably a fluorine compound, mixed with a carrier gas. Any sodium or lithium contained in the grains of natural or synthetic silica react with the fluorine or chlorine of the fluorine or chlorine compound, thereby making it possible to improve the optical quality of fibers drawn from a preform built up with natural or synthetic silica, and to do so at reduced cost.

Abstract: Natural or synthetic silica is deposited on a preform set into rotation in front of a plasma torch which moves back and forth substantially parallel to a longitudinal direction of the preform, a first feed duct feeds the plasma with grains of natural or synthetic silica while a second feed duct feeds the plasma with a fluorine or chlorine compound, preferably a fluorine compound, mixed with a carrier gas. Any sodium or lithium contained in the grains of natural or synthetic silica react with the fluorine or chlorine of the fluorine or chlorine compound, thereby making it possible to improve the optical quality of fibers drawn from a preform built up with natural or synthetic silica, and to do so at reduced cost.

Abstract: Natural or synthetic silica is deposited on a preform set into rotation in front of a plasma torch which moves back and forth substantially parallel to a longitudinal direction of the preform, a first feed duct feeds the plasma with grains of natural or synthetic silica while a second feed duct feeds the plasma with a fluorine or chlorine compound, preferably a fluorine compound, mixed with a carrier gas. Any sodium or lithium contained in the grains of natural or synthetic silica react with the fluorine or chlorine of the fluorine or chlorine compound, thereby making it possible to improve the optical quality of fibers drawn from a preform built up with natural or synthetic silica, and to do so at reduced cost.

Abstract: The deposit of natural or synthetic silica comprises a preform (1) set into rotation (7) in front of a plasma torch (3) which moves back and forth substantially parallel to a longitudinal direction (L) of the preform (1), a feed duct (9) for feeding the plasma with grains of natural or synthetic silica (11), characterized in that the same feed duct (9) feeds the plasma with a fluorine or chlorine compound, preferably a fluorine compound, mixed with a carrier gas (15). Sodium or lithium contained in the grains of natural or synthetic silica reacts with the fluorine or chlorine of the fluorine or chlorine compound, making it possible to improve the optical quality of fibers built up with the natural or synthetic silica at reduced cost.