The use of ultra-wide band (UWB) radio technique is proposed as a viable solution for the distribution of highdefinition audio/video content in fiber-to-the-home (FTTH) networks. The approach suitability is demonstrated by the transmission of standards-based UWB signals at 1.25 Gbit/s along different FTTH fiber links with 25 km up to 60 km of standard single-mode fiber length in a laboratory experiment. Experimental results suggest that orthogonal frequency division multiplexed UWB signals exhibit better transmission performance in FFTH networks than impulse radio UWB signals. Index Terms-Optical communications, Fiber-To-The-Home access networks, Ultra-Wide Band (UWB). I. INTRODUCTION ltra-Wide Band (UWB) has been indicated as one of the most promising techniques to be used in wireless communication networks. The growing interest in this technique is due to its low self-interference, tolerance to multipath fading, low probability of interception and capability of passing through walls while maintaining the communication [1]. Nowadays, UWB is appointed for high bit-rate wireless communications at picocell range, namely as a replacement of high definition (HD) video/audio cabling [2]. This paper proposes to extend this application to the distribution of HD audio/video content by the optical modulation and transmission of UWB signals in their native format through fiber-to-the-home (FTTH) access networks. This approach exhibits several advantages: (i) FTTH networks provide bandwidth enough to distribute a large number of UWB signals, as each one of them can occupy up to 7 GHz in current UWB regulation [3]. (ii) No trans-modulation is required at user premises. HD audio/video content is transmitted through the fibers in UWB native format. (iii) No frequency up-conversion is required at customer premises. The UWB signals are photo-detected, filtered, amplified and radiated directly to establish the wireless connection. (iv) FTTH networks are transparent to the specific UWB implementation Manuscript received 6th December 2007.

Gomes, N.; Morant, M.; Alphones, A.; Cabon, B.; Mitchell, J.; Lethien, C.; Csörnyei, M.... (2009). Radio-over-fiber transport for the support of wireless broadband services. Journal of Optical Networking. 8(2):156-178. https://doi.Some of the work carried out within the EU Network of Excellence ISIS on radio over fiber systems for the support of current and emerging wireless networks is reviewed. Direct laser modulation and externally modulated links have been investigated, and demonstrations of single-mode fiber and multimode fiber systems are presented. The wireless networks studied range from PANs (such as ZigBee and UWB) through wireless LANs to wireless MANs (WiMAX) and third generation mobile communications systems. The performance of the radio over fiber transmission is referenced to the specifications of the relevant standard, protocol operation is verified and complete network demonstrations have been implemented.

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Abstract:In this paper, we evaluate experimentally and model theoretically the intra-and inter-core crosstalk between the polarized core modes in single-mode multi-core fiber media including temporal and longitudinal birefringent effects. Specifically, extensive experimental results on a four-core fiber indicate that the temporal fluctuation of fiber birefringence modifies the intra-and inter-core crosstalk behavior in both linear and nonlinear optical power regimes. To gain theoretical insight into the experimental results, we introduce an accurate multi-core fiber model based on local modes and perturbation theory, which is derived from the Maxwell equations including both longitudinal and temporal birefringent effects. Numerical calculations based on the developed theory are found to be in good agreement with the experimental data.

Single-wall carbon nanotube deposition on the cladding of optical fibers has been carried out to fabricate an all-fiber nonlinear device. Two different nanotube deposition techniques were studied. The first consisted of repeatedly immersing the optical fiber into a nanotube supension, increasing the thickness of the coating in each step. The second deposition involved wrapping a thin film of nanotubes around the optical fiber. For both cases, interaction of transmitted light through the fiber core with the external coating was assisted by the cladding mode resonances of a tilted fiber Bragg grating. Ultrafast nonlinear effects of the nanotube-coated fiber were measured by means of a pump-probe pulses experiment. © 2011 OCIS codes: 060.3735, 060.4370, 160.4236.Single-wall carbon nanotubes (SWNTs) have found innovative applications in the optical field due to their nonlinear properties in the near IR. Depending on the chirality of SWNTs, they can be either metallic or semiconducting, the latter being the desired behavior for nonlinear optical performance. Many optical applications could benefit from using SWNTs as nonlinear materials, such as noise suppression, wavelength conversion, and passive mode-locking [1][2][3]. A challenge when designing SWNT-based devices is incorporating the nanotubes in such a way as to enhance their interaction with light. One common method involves dispersing SWNTs in a solvent and spraying the solvent onto substrates in order to produce a nanotube film in the middle of a light beam [3]. Some inherent drawbacks in these configurations are the need for alignment and focusing stages, low SWNT burn thresholds, and low nonlinear interaction length. Solutions that overcome these challenges are based on SWNT deposition onto optical fibers. Tapered, D-shaped, and hollow optical fibers have been proposed to take advantage of the evanescent field interaction with SWNTs, distributing that interaction along the fiber length [4-6]. Nevertheless, manufacturing and handling these kinds of fibers is quite complex and delicate. In this work we propose for the first time SWNT deposition on standard optical fiber cladding for nonlinear applications. Interaction of light propagating through the fiber core with the outer SWNT coating is achieved via cladding mode resonances in a tilted fiber Bragg grating (TFBG). Two nanotube deposition methods have been carried out: dip-coating of the optical fiber in a SWNT suspension and wrapping of a SWNT film around the optical fiber. A TFBG is a kind of grating in which the index modulation planes are not orthogonal to the fiber axis but form a particular tilt angle. This inclination enhances the coupling of light from core mode to counterpropagating cladding mode resonances. Consequently, the grating transmission response is a multinotch response consisting of numerous cladding mode resonances in addition to the core mode resonance [see Fig. 1(a)]. The transverse mode profile of cladding modes spreads to the cladding of the fiber and interacts with the outer mediu...