Abstract: A method for selecting wide-band multimode optical fibers from a single wavelength, the method comprising the following steps of, for each multimode optical fiber obtaining a first DMD plot using a measurement of DMD carried out at a first single wavelength, obtaining from the first DMD plot, a first multimode fiber specification parameter; and for each fiber: obtaining from the first DMD plot, a curve representative of a radial offset delay, called ROD curve, as a function of the radial offset value; applying a linear fit on the ROD curve for at least two radial offset value ranges; obtaining from the linear fit and for each radial offset value range, an average radial offset delay slope, called ROD slope; selecting the multimode optical fibers meeting a first predetermined specification criterion for the first multimode fiber performance parameter, and for which the at least two computed ROD slopes meet a predetermined slope criterion.

Abstract: A method of qualifying an effective bandwidth of a multimode optical fiber at a first wavelength ?1, using DMD data of the fiber measured a second wavelength ?2. Data representative of a Radial Offset Delay, a Radial Offset Bandwidth and a Relative Radial Coupled Power of the fiber are derived from the DMD data at the second wavelength ?2. A transformation is performed on the ROD data and ROB data at the second wavelength ?2 to obtain corresponding ROD data and ROB data at the first wavelength ?1. An effective bandwidth of the fiber at the second wavelength ?2 is computed using the ROD data and the ROB data at the first wavelength ?1 and the {tilde over (P)}DMD data at the second wavelength ?2.

Abstract: A method of qualifying an effective bandwidth of a multimode optical fiber at a first wavelength ?1, using DMD data of the fiber measured a second wavelength ?2. Data representative of a Radial Offset Delay, a Radial Offset Bandwidth and a Relative Radial Coupled Power of the fiber are derived from the DMD data at the second wavelength ?2. A transformation is performed on the ROD data and ROB data at the second wavelength ?2 to obtain corresponding ROD data and ROB data at the first wavelength ?1. An effective bandwidth of the fiber at the second wavelength ?2 is computed using the ROD data and the ROB data at the first wavelength ?1 and the {tilde over (P)}DMD data at the second wavelength ?2.

Abstract: A method for selecting wide-band multimode optical fibers from a single wavelength, the method comprising the following steps of, for each multimode optical fiber obtaining a first DMD plot using a measurement of DMD carried out at a first single wavelength, obtaining from the first DMD plot, a first multimode fiber specification parameter; and for each fiber: obtaining from the first DMD plot, a curve representative of a radial offset delay, called ROD curve, as a function of the radial offset value; applying a linear fit on the ROD curve for at least two radial offset value ranges; obtaining from the linear fit and for each radial offset value range, an average radial offset delay slope, called ROD slope; selecting the multimode optical fibers meeting a first predetermined specification criterion for the first multimode fiber performance parameter, and for which the at least two computed ROD slopes meet a predetermined slope criterion.

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. A multimode fiber for Ethernet optical system with an improved bandwidth is thus obtained.

Abstract: The present invention embraces an optical fiber that includes a central core having an alpha refractive index profile with respect to an outer optical cladding. The optical fiber also includes an inner cladding and a buried trench. The central core includes a core matrix doped with at least fluorine and a dopant element that increases refractive index. The optical fiber typically has reduced bending losses and cladding effect as well as a high bandwidth at the wavelengths of 850 nanometers and 1300 nanometers for high-data-rate applications.

Abstract: The present invention embraces a multimode optical fiber that includes a central core having an alpha-index profile, an inner cladding, a depressed trench, and an outer cladding (e.g., an outer optical cladding). Typically, the central core's alpha-index profile has a minimum refractive index at the central core's radius that corresponds to a refractive index difference with respect to the outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

Abstract: The present invention embraces an optical fiber that includes a central core having an alpha-index profile with respect to an outer cladding. The optical fiber also includes an inner cladding, a depressed trench, and an outer cladding. Typically, the alpha-index profile of the central core is interrupted at a point having a positive refractive index difference with respect to the outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

Abstract: A multimode optical fiber includes a central core having a graded-index profile with a delta value of about 1.9 percent or greater. The graded-index core profile has at least two different alpha parameter values along the core radius, namely a first value in an inner zone of the central core and a second value in an outer zone of the central core. The second alpha parameter value is typically less than the first alpha parameter value. The graded-index core profile and its first derivative are typically substantially continuous over the width of the graded-index core.

Abstract: A multimode optical fiber includes a central core having a graded-index profile with a delta value of about 1.9 percent or greater. The graded-index core profile has at least two different alpha parameter values along the core radius, namely a first value in an inner zone of the central core and a second value in an outer zone of the central core. The second alpha parameter value is typically less than the first alpha parameter value. The graded-index core profile and its first derivative are typically substantially continuous over the width of the graded-index core.

Abstract: The present invention embraces an optical fiber that includes a central core having an alpha refractive index profile with respect to an outer optical cladding. The optical fiber also includes an inner cladding and a buried trench. The central core includes a core matrix doped with at least fluorine and a dopant element that increases refractive index. The optical fiber typically has reduced bending losses and cladding effect as well as a high bandwidth at the wavelengths of 850 nanometers and 1300 nanometers for high-data-rate applications.

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. A multimode fiber for Ethernet optical system with an improved bandwidth is thus obtained.

Abstract: The present invention relates to a method for manufacturing a preform for optical fibers via a vapor deposition process in which the position of the reversal point near the substrate tube's supply side shifts along the longitudinal axis of the substrate tube during at least part of the deposition process.

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: The present invention embraces a multimode optical fiber that includes a central core having an alpha-index profile, an inner cladding, a depressed trench, and an outer cladding (e.g., an outer optical cladding). Typically, the central core's alpha-index profile has a minimum refractive index at the central core's radius that corresponds to a refractive index difference with respect to the outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

Abstract: The present invention embraces an optical fiber that includes a central core having an alpha-index profile with respect to an outer cladding. The optical fiber also includes an inner cladding, a depressed trench, and an outer cladding. Typically, the alpha-index profile of the central core is interrupted at a point having a positive refractive index difference with respect to the outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

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: The present invention relates to a method for manufacturing a preform for optical fibers via a vapor deposition process in which the position of the reversal point near the substrate tube's supply side shifts along the longitudinal axis of the substrate tube during at least part of the deposition process.