Fibre impairment compensation using artificial neural network equalizer for high-capacity coherent optical OFDM signals

We propose an artificial neural network (ANN) equalizer for transmission performance enhancement of coherent optical OFDM (C-OOFDM) signals. The ANN equalizer showed more efficiency in combating both chromatic dispersion (CD) and single-mode fibre (SMF)-induced non-linearities compared to the least mean square (LMS). The equalizer can offer a 1.5 dB improvement in optical signal-to-noise ratio (OSNR) compared to LMS algorithm for 40 Gbit/s C-OOFDM signals when considering only CD. It is also revealed that ANN can double the transmission distance up to 320 km of SMF compared to the case of LMS, providing a nonlinearity tolerance improvement of ∼0.7 dB OSNR.

High resolution optical time-domain reflectometry based on correlation utilizing an all-fiber chaotic source

We propose a high-resolution optical time domain reflectometry (OTDR) based on an all-fiber supercontinuum source. The source simply consists of a laser with moderate power and a section of fiber which has a zero dispersion wavelength near the laser's central wavelength. Spectrum and time domain properties of the source are investigated, showing that the source has great capability in nonlinear optics, such as correlation OTDR. We analyze one of the key factors limiting the operational range of such an OTDR, i.e., sampling time. Finally, we experimentally demonstrate a correlation OTDR with 25km sensing range and 5.3cm spatial resolution, as a verification of theoretical analysis.

Inbound logistics, the last mile and intermodal high capacity transport – the case of Jula in Sweden

Some of the biggest challenges for intermodal transport competitiveness are the extra handling costs and pre- and post-haulage costs. This paper investigates the use of Intermodal High Capacity Transport (IHCT) for the intermodal transport chain in general and to pre-and post-haulage in particular. The aim is not only to measure the cost reductions from using larger vehicles but to understand how better management of inbound flows through increased integration of logistics processes can increase the efficiency of the last mile. The paper analyses the haulage of two 40 foot containers simultaneously when part of an intermodal transport chain. Data were collected from a demonstration project in Sweden, where permission was obtained to use longer vehicles on an approved route to and from the nearest intermodal terminal. Results indicate substantial cost savings from using longer vehicles for pre- and post-haulage. In addition, the business model whereby the shipper purchased their own chassis and permission was obtained to access the terminal after hours for collecting pre-loaded chassis brought additional cost and planning benefits. The total cost saving was significant and potentially eliminates the cost deficit associated with the last mile.

Inbound logistics, the last mile and intermodal high capacity transport.

Some of the biggest challenges for intermodal transport competitiveness are the extra handling costs and pre- and post-haulage costs. This paper investigates the use of Intermodal High Capacity Transport (IHCT) for the intermodal transport chain in general and to pre-and post-haulage in particular. The aim is not only to measure the cost reductions from using larger vehicles but to understand how better management of inbound flows through increased integration of logistics processes can increase the efficiency of the last mile. The paper analyses the haulage of two 40 foot containers simultaneously when part of an intermodal transport chain. Data were collected from a demonstration project in Sweden, where permission was obtained to use longer vehicles on an approved route to and from the nearest intermodal terminal. Results indicate substantial cost savings from using longer vehicles for pre- and post-haulage. In addition, the business model whereby the shipper purchased their own chassis and permission was obtained to access the terminal after hours for collecting pre-loaded chassis brought additional cost and planning benefits. The total cost saving was significant and potentially eliminates the cost deficit associated with the last mile.

3D Fe2(MoO4)3 microspheres with nanosheet constituents as high-capacity anode materials for lithium-ion batteries

Three-dimensional (3D) Fe2(MoO4)3 microspheres with ultrathin nanosheet constituents are first synthesized as anode materials for the lithium-ion battery. It is interesting that the single-crystalline nanosheets allow rapid electron/ion transport on the inside, and the high porosity ensures fast diffusion of liquid electrolyte in energy storage applications. The electrochemical properties of Fe2(MoO4)3 as anode demonstrates that 3D Fe2(MoO4)3 microspheres deliver an initial capacity of 1855 mAh/g at a current density of 100 mA/g. Particularly, when the current density is increased to 800 mA/g, the reversible capacity of Fe2(MoO4)3 anode still arrived at 456 mAh/g over 50 cycles. The large and reversible capacities and stable charge–discharge cycling performance indicate that Fe2(MoO4)3 is a promising anode material for lithium battery applications. Graphical abstract The electrochemical properties of Fe2(MoO4)3 as anode demonstrates that 3D Fe2(MoO4)3 microspheres delivered an initial capacity of 1855 mAh/g at a current density of 100 mA/g. When the current density was increased to 800 mA/g, the Fe2(MoO4)3 still behaved high reversible capacity and good cycle performance.

High sensitive Static fiber Bragg grating strain sensing using lasers locked to relative frequency reference

A novel high sensitive fiber Bragg grating (FBG) strain sensing technique using lasers locked to relative frequency reference is proposed and analyzed theoretically. Static strain on FBG independent of temperature can be measured by locking frequency of diode laser to the mid reflection frequency of matched reference FBG, which responds to temperature similar to that of the sensor FBG, but is immune to strain applied to the same. Difference between light intensities reflected from the sensor and reference FBGs (proportional to the difference between respective pass band gains at the diode laser frequency) is not only proportional to the relative strain between the sensor and reference FBGs but also independent of servo residual frequency errors. Usage of relative frequency reference avoids all complexities involved in the usage of absolute frequency reference, hence, making the system simple and economical. Theoretical limit for dynamic and static strain sensitivities considering all major noise contributions are of the order of 25 (p epsilon) / root Hz and 1.2 n epsilon / root Hz respectively.

In-situ Stabilization of Tin Nanoparticles in Porous Carbon Matrix derived from Metal Organic Framework: High Capacity and High Rate Capability Anodes for Lithium-ion Batteries

It is a formidable challenge to arrange tin nanoparticles in a porous matrix for the achievement of high specific capacity and current rate capability anode for lithium-ion batteries. This article discusses a simple and novel synthesis of arranging tin nanoparticles with carbon in a porous configuration for application as anode in lithium-ion batteries. Direct carbonization of synthesized three-dimensional Sn-based MOF: K2Sn2(1,4-bdc)(3)](H2O) (1) (bdc = benzenedicarboxylate) resulted in stabilization of tin nanoparticles in a porous carbon matrix (abbreviated as Sn@C). Sn@C exhibited remarkably high electrochemical lithium stability (tested over 100 charge and discharge cycles) and high specific capacities over a wide range of operating currents (0.2-5 Ag-1). The novel synthesis strategy to obtain Sn@C from a single precursor as discussed herein provides an optimal combination of particle size and dispersion for buffering severe volume changes due to Li-Sn alloying reaction and provides fast pathways for lithium and electron transport.

Sensitive detection of C-reactive protein using optical fiber Bragg gratings

An accurate and highly sensitive sensor platform has been demonstrated for the detection of C-reactive protein (CRP) using optical fiber Bragg gratings (FBGs). The CRP detection has been carried out by monitoring the shift in Bragg wavelength (Delta lambda(B)) of an etched FBG (eFBG) coated with an anti-CRP antibody (aCRP)-graphene oxide (GO) complex. The complex is characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. A limit of detection of 0.01 mg/L has been achieved with a linear range of detection from 0.01 mg/L to 100 mg/L which includes clinical range of CRP. The eFBG sensor coated with only aCRP (without GO) show much less sensitivity than that of aCRP-GO complex coated eFBG. The eFBG sensors show high specificity to CRP even in the presence of other interfering factors such as urea, creatinine and glucose. The affinity constant of similar to 1.1 x 10(10) M-1 has been extracted from the data of normalized shift (Delta lambda(B)/lambda(B)) as a function of CRP concentration. (C) 2014 Elsevier B.V. All rights reserved.

Polymer-Optical-Fiber Lasers and Amplifiers Doped with Organic Dyes

Polymer optical fibers (POFs) doped with organic dyes can be used to make efficient lasers and amplifiers due to the high gains achievable in short distances. This paper analyzes the peculiarities of light amplification in POFs through some experimental data and a computational model capable of carrying out both power and spectral analyses. We investigate the emission spectral shifts and widths and on the optimum signal wavelength and pump power as functions of the fiber length, the fiber numerical aperture and the radial distribution of the dopant. Analyses for both step-index and graded-index POFs have been done.

Field and dispersion properties of subwavelength-diameter hollow optical fiber

We have investigated the basic properties of subwavelength-diameter hollow optical fiber with exact solutions of Maxwell's equations. The characteristics of modal field and waveguide dispersion have been studied. It shows that the subwavelength-diameter hollow optical fibers have interesting properties, such as enhanced evanescent field, local enhanced intensity in the hollow core and large waveguide dispersion that are very promising for many miniaturized high performance and novel photonic devices. (C) 2007 Optical Society of America.

Field enhancement and power distribution characteristics of subwavelength-diameter terahertz hollow optical fiber

Fields in subwavelength-diameter terahertz hollow optical fiber (STHOF) can be intensified by large discontinuity of the electric field at high index contrast interfaces. The influences of fiber geometry and refractive index of the dielectric region on the fiber characteristics, such as power distribution, enhancement factor, have been discussed in detail. By appropriate design, the intensity in the central region of STHOF may be enhanced by a factor of greater than 1.5 compared with subwavelength-diameter terahertz fiber without the central hole and the loss can be reduced. For its compact structure and simple fabrication process, the fiber may be very useful in many miniaturized high performance and novel terahertz photonic devices. (c) 2007 Elsevier B.V. All rights reserved.