Ofs Fitel, LLC

Ofs Fitel Llc, a Delaware Limited Liability Company

Benyuan Zhu

David John DiGiovanni

Paul S Westbrook

Man Fei Yan

Thierry Franck Taunay

John Michael Fini

Patrick William Wisk

David W Peckham

Tommy Geisler

Dennis J Trevor

Peter Ingo Borel

Jorgen Ostgaard Olsen

Ole A Levring

Jeffrey W Nicholson

Yaowen Li

William R Holland

Kazi S Abedin

Rasmus V S Jensen

Yingzhi Sun

Rasmus V Jensen

David J Digiovanni

Thierry F Taunay

A fiber amplifier that is particularly configured to provide gain across a large extent of the C-band spectral range (i.e., a gain bandwidth of at least 42 nm, preferably within the range of 46-48 nm) utilizes a specially-designed discrete Raman amplifier in combination with a high inversion level EDFA to extend the gain bandwidth of a conventional EDFA C-band optical amplifier, while maintaining the gain ripple below an acceptable value. The EDFA provides operation at a highly-inverted level and the specialized discrete Raman amplifier (sDRA) element has particular parameters (dispersion, length, effective area) selected to maintain operation within a 'small gain' regime while also extending the long wavelength edge of the gain bandwidth and reducing the gain ripple attributed to the EDFA component.

Wide gain bandwidth C-band optical fiber amplifier

A fiber-based optical amplifying system for use with a multi-wavelength input optical signal operating over a predetermined bandwidth is specifically configured to eliminate the need for a separate gain-flattening filter, improving the power conversion efficiency (PCE) of the system. Both a distributed Raman amplifier (DRA) and an erbium-doped fiber amplifier (EDFA) are used, where the DRA component is configured to use a pump beam with at a power level no greater than 200 mW. The EDFA is configured to exhibit a gain profile the complements that of the DRA, while also providing amplification that is no less than 10dB at any wavelength within the system bandwidth. With these parameters, the combination of the DRA and EDFA is able to maintain an output gain deviation of less than about 2 dB.

Complementary optical fiber-based amplifiers with built-in gain flattening

An optical fiber has a core region that is doped with one or more viscosity-reducing dopants in respective amounts that are configured, such that, in a Raman spectrum with a frequency shift of approximately 600 cm, the fiber has a nanoscale structure having an integrated D2 line defect intensity of less than 0.025. Alternatively, the core region is doped with one or more viscosity-reducing dopants in respective amounts that are configured such that the fiber has a residual axial compressive stress with a stress magnitude of more than 20 MPa and a stress radial extent between 2 and 7 times the core radius. According to another aspect of the invention a majority of the optical propagation through the fiber is supported by an identified group of fiber regions comprising the core region and one or more adjacent cladding regions. The fiber regions are doped with one or more viscosity-reducing dopants in respective amounts and radial positions that are configured to achieve viscosity matching among the fiber regions in the identified group.

Optical fiber with low loss and nanoscale structurally homogeneous core

An optical pedestal fiber is configured to be taperable to form a tapered fiber having a mode field diameter at the tapered end that differs from the mode field diameter at the untapered end in correspondence with the difference between the cladding diameter at the tapered end and the cladding diameter at the untapered end. A plurality of such pedestal fibers can be used to construct a tapered fiber bundle coupler that provides matching of both core pitch and mode field diameter between a plurality of input fibers and individual cores of a multicore fiber. Further, the tapered fiber bundle coupler can be constructed using a plurality of fibers, in which individual fibers are configured to have different effective refractive indices, thereby suppressing crosstalk therebetween.

Techniques and devices for low-loss coupling to a multicore fiber

In a TDM- and WDM-based FBG sensor array system, a source emits a light covering a selected wavelength range. The light is amplified and then used to generate a series of pulses that are fed into an array of sensor gratings. The propagation of a pulse through the sensor array results in a time-domain-multiplexed output, comprising a series of output pulses in which each output pulse comprises a reflection of the input pulse at a respective grating in the sensor array. Raman amplification is used to amplify both the pulse input into and the time-domain multiplexed output from the sensor array, which is then coupled into an output processing stage for receiving the sensor output and for reconstructing the wavelength output of each grating in the sensor array. The wavelength change for each grating is then used to calculate a physical parameter(s) to be measured, such as temperature and/or strain.

TDM- and WDM-based FBG sensor array system

A passive, coexisting 10 Gb/s passive optical network (XGPON) and Gb/s passive optical network (GPON) is created by using a pair of counter-propagating laser pump sources at a network-based optical line terminal, in combination with a feeder fiber, to create distributed Raman amplification for the upstream signals associated with both GPON and XGPON systems. A passive remote node is located at the opposite end of the feeder fiber, in the vicinity of a group of end-user locations, and includes a cyclic WDM and a pair of power splitters for the GPON and XGPON signals such that the GPON signals are thereafter directed through a first power splitter into optical network units (ONUs) specifically configured for GPON wavelengths and XGPON signals are directed through a second power splitter into ONUs configured for the XGPON wavelengths. The arrangement of the remote node allows for the reach and split ratios of the GPON and XGPON systems to be individually designed for optimum performance.

Arrangement for deploying co-existing GPON and XGPON optical communication systems

Systems and methods for reducing cost and amplifier module size are disclosed. One system comprises an arrayed optical fiber amplifier that uses a ribbonized fiber that permits reduction of amplifier module size and also reduction in the cost of manufacturing that are not readily achievable in other currently-available systems.

Arrayed optical fiber amplifier using ribbonized erbium-doped fiber

A discrete Raman amplifier comprises a Raman gain fiber, an input port into the Raman gain fiber for receiving optical signals to be Raman amplified, and an output port out of the Raman gain fiber for emitting Raman-amplified optical signals. A pump light input provides pump light to the Raman gain fiber at a plurality of wavelengths so as to provide Raman amplification over the selected signal wavelength range. Within both the pump light wavelength range and the selected signal wavelength range, the Raman gain fiber has only positive chromatic dispersion, and the Raman gain fiber has a moderate effective area.

Discrete raman amplifier

An optical fiber has two or more core regions disposed within a common cladding region. Each of the core regions is configured to guide a respective light transmission comprising at least one optical mode along the length of the fiber. The cores are arranged within the common cladding region according to a core configuration that substantially prevents crosstalk between modes of neighboring cores in the fiber, in a deployment of the fiber in which cross-coupling between neighboring cores is affected by perturbations arising in the deployed fiber.

Techniques for reducing crosstalk in multicore fibers

A high-powered double cladding (DC) pumped Ytterbium-free L-band Erbium doped fiber amplifier (EDFA) for dense-wavelength-division multiplexing (DWDM) is disclosed. The DC pumped Ytterbium-free L-band EDFA comprises a length of DC Erbium-doped fiber (EDF) that has a low-index, large-diameter core. For some embodiments, the DC-EDF also comprises a trench that is located radially exterior to the cladding, thereby increasing cladding absorption while still effectively maintaining single-mode behavior.

High-power double-cladding-pumped (DC) erbium-doped fiber amplifier (EDFA)

A double-clad (DC) multicore (MC) Erbium-doped fiber amplifier (EDFA) for dense-wavelength-division multiplexing (DWDM) is disclosed. The DC-MC-EDFA comprises a length of DC-MC Erbium-doped fiber (EDF) that is core-matched spliced to a MC tapered signal-pump fiber combiner (TFC). For some embodiments, the optical signals are coupled into the DC-MC-EDF by the MC-TFC, and the pump energy is also coupled into the DC-MC-EDF by the MC-TFC. For some embodiments, the optical signals are also transmitted out of the DC-MC-EDF through the MC-TFC.

Multi-core erbium-doped fiber amplifier

A multicore optical fiber includes a plurality of core regions disposed within a common cladding region. Each of the plurality of core regions is configured, in combination with the common cladding region, to propagate light along a longitudinal axis of the fiber. At least two core regions are configured to inhibit resonant coupling of propagated light therebetween within a selected region of operation. At least one segment of the fiber includes a twist that is configured such that when the twisted segment is subjected to a bend having a selected radius, the twist creates a controlled change in the amount of crosstalk between the at least two core regions, compared with the amount of crosstalk between the at least two core regions when a bend having the selected radius is introduced into a non-twisted segment of the fiber.

Techniques for manipulating crosstalk in multicore fibers

An optical fiber coupler connects transmission multicore optical fiber (TMCF) with an amplifier multicore optical fiber (AMCF) and a plurality of optical pump fibers. The coupler includes a plurality of signal cores extending between a multicore input endface and a coupler output endface, and a plurality of pump cores extending between a pump input and the coupler output endface. The multicore input endface is connectable to the TMCF, and the pump input is connectable to the optical pump fibers. Each pump core is paired with a corresponding signal core to form a core pair that is adiabatically tapered such that signal light carried by the signal core is combined with pump light carried by the pump core. The coupler output endface is connectable to the AMCF such that the combined light output of each core pair is provided as an input to a respective AMCF core.

Growing community of inventors

Princeton, NJ, United States of America

Benyuan Zhu