Leandro L.,Technical University of Denmark |
Gruner-Nielsen L.,OFS |
Rottwitt K.,Technical University of Denmark
Optics Letters | Year: 2015
The increasing use of few-mode fibers for high-speed optical communication systems in space division multiplexing has created a need for mode resolved characterization of few-mode fibers. In this Letter, we present a new method to characterize the bend loss of the individual modes in a few-mode fiber. This procedure uses a simple setup for spatially and spectrally resolved imaging and allows the measurement of the bend loss of each and every guided mode at once. It does not require the use of mode converters in contrast to other methods. Results for graded-index two- and four-mode fibers are presented, together with comparisons against direct bend-loss measurements for the four-mode and standard single-mode fibers. © 2015 Optical Society of America.
Lightwave | Year: 2011
Various network providers are competing to minimize latency in long-haul networks and are identifying applications in which transport time is critical and latency must be considered. In these situations, selecting the right transmission fiber can shave hundreds of microseconds off the transport time. An important key driver for lower latency is validation of transferred data, in which the optical transport of data between the two locations must be transparent. When data passes back and forth between computers, minimizing latency helps ensure efficient data transfer. Use of optical fiber with ultra-low PMD offers one way to avoid signal regeneration, while optical-fiber based dispersion compensation module is the most typical method of correcting dispersion. A more functional solution balances the dispersion in the route by using positive- and negative-dispersion segments similar to the practice in submarine cables.
Kuo B.P.-P.,University of California at San Diego |
Fini J.M.,OFS Laboratories |
Gruner-Nielsen L.,OFS |
Radic S.,University of California at San Diego
Optics Express | Year: 2012
Conventional highly-nonlinear fiber (HNLF) designs are optimized for high field-confinement but are also inherently susceptible to dispersion fluctuations. The design compromise prevents fiber-optical parametric mixers from possessing high power efficiency and extended operating bandwidth simultaneously. Using a new fiber waveguide design, we have fabricated and tested a new class of HNLF that possesses a significantly lower level of dispersion fluctuations while maintaining a high level of field-confinement comparable to that in conventional HNLFs. The fiber was used to demonstrate an all-fiber parametric oscillator operating in short-wavelength infrared (SWIR) band with a watt-level pumpfor the first time. © 2012 Optical Society of America.
Tong Z.,Chalmers University of Technology |
Lundstrom C.,Chalmers University of Technology |
Andrekson P.A.,Chalmers University of Technology |
McKinstrie C.J.,Alcatel - Lucent |
And 6 more authors.
Nature Photonics | Year: 2011
In principle, optical phase-sensitive amplifiers are known to be capable of realizing noiseless amplification, as well as improving the signal-to-noise-ratio of optical links by 3 dB compared to conventional, phase-insensitively amplified links. However, current state-of-the-art phase-sensitive amplifiers are still far from being practical, lacking, for example, significant noise performance improvement, broadband gain and modulation-format transparency. Here, we demonstrate experimentally, for the first time, an optical-fibre-based non-degenerate phase-sensitive amplifier link consisting of a phase-insensitive parametric copier followed by a phase-sensitive amplifier that provides broadband amplification, signal modulation-format independence, and nearly 6 dB link noise-figure improvement over conventional, erbium-doped fibre amplifier-based links. The PSA has a record-low 1.1 dB noise figure, and can be extended to work with multiple wavelength channels with modest system complexity. This concept can also be realized in other materials with third-order nonlinearities, and is useful in any attenuation-limited optical link. © 2011 Macmillan Publishers Limited. All rights reserved.
Zhu B.,OFS Laboratories |
Chandrasekhar S.,Alcatel - Lucent |
Liu X.,Alcatel - Lucent |
IEEE Photonics Technology Letters | Year: 2011
We experimentally compare the transmission performance of a 485-Gb/s coherent optical orthogonal frequency-division-multiplexed (CO-OFDM) superchannel with PDM-16QAM subcarrier modulation over two types of fiber links, one based on ultra-large-area fiber (ULAF) spans, and the other on standard single-mode-fiber (SSMF) spans. Two amplification schemes, hybrid Raman/erbium-doped fiber amplifier (EDFA) and EDFA-only, are studied. We find that the optimum signal launch power is about 2 dB higher in ULAF than in SSMF for transmitting over 20 80-km spans under both amplification schemes. With EDFA-only amplification, the ULAF offers ∼ 2-dB higher optimum Q 2 factor than the SSMF after 1600-km transmission. With hybrid Raman/EDFA amplification, a transmission distance of 1600 km is achieved at Q-2 =9.2∼dB by using the ULAF spans, which is 67% longer than that obtained with the SSMF spans. © 2011 IEEE.