Abstract: An optical signal transmission line includes a first fiber adapted to guide an optical signal therethrough and having a first ?, a second fiber adapted to guide the optical signal therethrough and having a second ? of less than or equal to about 100 nm at a wavelength of 1550 nm, and a ? compensating fiber adapted to guide the optical signal therethrough and having a third ? of greater than or equal to about 60 nm at a wavelength of 1550 nm. The first fiber, the second fiber and the ? compensating fiber are in optical communication, thereby defining an optical transmission line having a total dispersion and a total dispersion slope. The first ?, the second ? and the third ? cooperate such that the total dispersion is within the range of about 1.0 ps/nm-km?total dispersion?about ?1.0 ps/nm-km at a wavelength of 1550 nm, and the total dispersion slope is within the range of about 0.02 ps/nm2-km?total dispersion slope?about ?0.02 ps/nm2-km at a wavelength of 1550 nm.

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: Disclosed is a fiber optic module containing one or more optical fibers having an attenuator formed in the output end of the fibers to filter out unwanted higher order modes. The optical fibers are typically gain fibers or dispersion compensating fibers, and the attenuator consists of a coil, or a series of bends, of sufficient number and bend radius that higher order modes are reduced below a desired level.

Abstract: A system and method for controlling noise in a Raman amplifier including a plurality of pumps. A control system provides one or more control signals in response to an amplifier input or output signal. Pump parameters are adjusted in response to the control signals to achieve a desired noise figure characteristic.

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: Disclosed is a fiber optic module containing one or more optical fibers having an attenuator formed in the output end of the fibers to filter out unwanted higher order modes. The optical fibers are typically gain fibers or dispersion compensating fibers, and the attenuator consists of a coil, or a series of bends, of sufficient number and bend radius that higher order modes are reduced below a desired level.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a refractive index profile selected to provide dispersion at 1550 nm of between −90 and −150 ps/nm/km; dispersion slope at 1550 nm of less than −1.5 ps/nm2/km; and kappa of between 40 and 95. The profile preferably has a core surrounded by a cladding layer of refractive index &Dgr;c, and at least three radially adjacent regions including a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2, and an annular ring region having a refractive index &Dgr;3, wherein &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2.

Abstract: A device (16) in a system (10) modulates an optical signal (13) and tunes the duty cycle of the optical signal (13) for optimizing system performance as a response of the duty cycle. The device (16) includes a tunable duty-cycle Mach-Zehnder interferometer (MZI) acting as a pulse-width shaper (160) for modulating the optical signal (13) and tuning the duty cycle of the optical signal (13). The MZI (160) has a transmittance transfer function of the interferometer (160). At least one electrode structure (163) generates a DC voltage and an AC voltage for biasing and controlling the swing of the Mach-Zehnder interferometer (160) with the respective amplitudes of the DC and AC voltages such that the maximum power transmittance point on the transfer function is less than 100% for tuning the duty cycle of the optical signal (13) such that system performance is optimized.

Abstract: A device (16) in a system (10) modulates an optical signal (13) and tunes the duty cycle of the optical signal (13) for optimizing system performance as a response of the duty cycle. The device (16) includes a tunable duty-cycle Mach-Zehnder interferometer (MZI) acting as a pulse-width shaper (160) for modulating the optical signal (13) and tuning the duty cycle of the optical signal (13). The MZI (160) has a transmittance transfer function of the interferometer (160). At least one electrode structure (163) generates a DC voltage and an AC voltage for biasing and controlling the swing of the Mach-Zehnder interferometer (160) with the respective amplitudes of the DC and AC voltages such that the maximum power transmittance point on the transfer function is less than 100% for tuning the duty cycle of the optical signal (13) such that system performance is optimized.

Abstract: A system and method for controlling gain shape in a Raman amplifier including a plurality of pumps. The pumps produce a spectral distribution of output power characteristic. A feedback control system provides one or more feedback control signals in response to the amplifier output for adjusting pump parameters to achieve a desired spectral distribution of output power characteristic.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a refractive index profile selected to provide dispersion at 1550 nm of between −90 and −150 ps/nm/km; dispersion slope at 1550 nm of less than −1.5 ps/nm2/km; and kappa of between 40 and 95. The profile preferably has a core surrounded by a cladding layer of refractive index &Dgr;c, and at least three radially adjacent regions including a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2, and an annular ring region having a refractive index &Dgr;3, wherein &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index &Dgr;c. The core includes at least three radially adjacent regions, a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2 and an annular ring region having a refractive index &Dgr;3, such that &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2. The fiber exhibits a dispersion at 1550 which is less than −30 ps/nm/km, and a &kgr; value obtained by dividing the dispersion value by the dispersion slope which is between 40 and 100.

Abstract: An optical signal transmission line includes a first fiber adapted to guide an optical signal therethrough and having a first &kgr;, a second fiber adapted to guide the optical signal therethrough and having a second &kgr; of less than or equal to about 100 nm at a wavelength of 1550 nm, and a &kgr; compensating fiber adapted to guide the optical signal therethrough and having a third &kgr; of greater than or equal to about 60 nm at a wavelength of 1550 nm. The first fiber, the second fiber and the &kgr; compensating fiber are in optical communication, thereby defining an optical transmission line having a total dispersion and a total dispersion slope. The first &kgr;, the second &kgr; and the third &kgr; cooperate such that the total dispersion is within the range of about 1.0 ps/nm-km≧total dispersion≧about −1.0 ps/nm-km at a wavelength of 1550 nm, and the total dispersion slope is within the range of about 0.02 ps/nm2-km≧total dispersion slope≧about −0.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index &Dgr;c. The core includes at least three radially adjacent regions, a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2 and an annular ring region having a refractive index &Dgr;3, such that &Dgr;1 >&Dgr;3>&Dgr;c>&Dgr;2. The fiber exhibits a dispersion at 1550 which is less than −30 ps/nm/km, and a &kgr; value obtained by dividing the dispersion value by the dispersion slope which is between 40 and 100.

Abstract: An optical communication system including a transmitter, an optical information channel, and a receiver. The transmitter is configured to transmit a plurality of optical signals in L-band wavelengths or between about 1560 nm and about 1630 nm. Use of the L-band in long-haul optical systems permits transmission over at least about 2,000 kilometers from an originating light source such as a transmitter or another regenerator. A method of modulating and transmitting data signals in the L-band is also provided.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index &Dgr;c. The core includes at least three radially adjacent regions, a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2 and an annular ring region having a refractive index &Dgr;3, such that &Dgr;1>&Dgr;3>&Dgr;c>&Dgr;2. The fiber exhibits a dispersion slope which is less than −1.0 ps/nm2/km over the wavelength range 1525 to 1565, a dispersion at 1550 which is less than −30 ps/mn/km, and a &kgr; value obtained by dividing the dispersion value by the dispersion slope which is greater than 35 and preferably between 40 and 100.

Abstract: Disclosed is a dispersion compensating optical fiber that includes a core surrounded by a cladding layer of refractive index &Dgr;c. The core includes at least three radially adjacent regions, a central core region having &Dgr;1, a moat region having a refractive index &Dgr;2 and an annular ring region having a refractive index &Dgr;3, such that &Dgr;1 >&Dgr;3>&Dgr;c>&Dgr;2. The fiber exhibits a dispersion slope which is less than −1.0 ps/nm2/km over the wavelength range 1525 to 1565, a dispersion at 1550 which is less than −30 ps/mn/km, and a &kgr; value obtained by dividing the dispersion value by the dispersion slope which is greater than 35 and preferably between 40 and 100.