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Optical multi-band (OMB) systems exploit the low-loss spectrum of the single mode fiber (SMF) and are key enablers to increase the transportation capacity and node connectivity of already deployed systems. The realization of OMB systems is mainly based on the technological advances on the component and system level, and for this purpose, a broad gamut of various structural elements, such as transceivers, amplifiers, filters, etc. have been commercialized already or are close to commercialization. This wide range of options, which aid in unlocking the concurrent transmission in all amplification bands, is reviewed here for the first time, whilst their pros and cons as well as their limitations are discussed. Furthermore, the needs for additional components in order to fully exploit the -390 nm low-loss wavelength range of SMF, which spans from 1260 to 1650 nm, are highlighted. Finally, based on a physical layer formalism, which incorporates the impact of the most important physical layer constraints for an OMB system, the attainable capacity and transparent reach of each amplification band are quantified. [ABSTRACT FROM AUTHOR]

This paper investigates for rising optical fiber transmission strength, increasing bandwidth, and decreasing communication system weakness by using wavelength division multiplexing (WDM). WDM gives today's distention speed and communication traffic. Systems using WDM faces nonlinearities, which the most intensive nonlinear attack is, four wave mixing (FWM). FWM creates and increases crosstalk between WDM channels as a result slows down and impairs the performance of the communication system. This investigation uses orthogonal frequency division multiplexing (OFDM) for evaluating execution of WDM fiber system by repairing Polarization Mode Dispersion (PMD). We took results in the case of trying PMD-Emulator and without trying PMD-Emulator in the system design. We compared the results got in both cases. Furthermore, we compared the performance of the system with the investigations done using different ways, methods, and techniques for compensating PMD and FWM appears in WDM systems. As PMD-Emulator, helps enhancing the system design performance, and OFDM gives the feature of robustness and useful execution to the system. OFDM examined by appointing interfered orthogonal signal sets, for 16 channels; with equally spaced OFDM channels. Oure results showed that the optical fiber communication system using OFDM technique gives perfect removing FWM signal crosstalk, and accurate data transmission, comparing to other techniques used in other researches. We got a decreased FWM power to -77dBm, and the BER of -0.317. Furthermore, the system quality increased with applying PMD-Emulator and OFDM. In addition, using PMD-Emulator in the system design raised the results effectiveness. The program used in the present work is optisystem-15, and the results obtained in this study coincide with the theoretical and actual results obtained by the previous studies. [ABSTRACT FROM AUTHOR]

At present days, metropolitan and access communication networks are markedly developing utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play a key role. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention for the next generation optical metropolitan and access networked systems. Simultaneously, the utilization of common optical network resources in wavelength domains will be more important. The main purpose of this paper is presented by the evaluation of resource efficiencies for the non-symmetric dynamic wavelength allocation method applied in the WDM-PON network design with a conventional topology. This contribution introduces a novel non-symmetric Dynamic Wavelength Allocation (DWA) method for a selected network design with the utilization only passive optical splitters in remote nodes. This novel wavelength allocation method is oriented on minimizing a number of working wavelengths that will be used for compliance of customers' requests for data transmitting in the common point-to-multipoint WDM–PON network design. For evaluation of wavelength scheduling, a simulation model related to the conventional WDM-PON network design is realized in the MATLAB programming environment is presented with results. Finally, different traffic loading scenarios are determined and, subsequently, resource efficiencies of the presented non-symmetric DWA method are evaluated from a viewpoint of application in future WDM-PON network designs. [ABSTRACT FROM AUTHOR]

The transfer and synchronization of high-precision frequency are crucial for various application fields. Recently, the fiber link has become an attractive option for long-haul frequency dissemination. In this paper, we demonstrate a stable radio-frequency (RF) fiber-based transmission system with passive compensation method by frequency mixing. Different from previous solutions, single wavelength of the optical carriers is employed in the proposed system to maintain the transmission symmetry. The frequency-tripled signal at the local end is utilized to avoid the effects of backward Rayleigh scattering and mitigate the interference from the phase-conjugated signal. Additionally, instead of tracking the phase drift of the fiber link like an active compensation, the remote reconstruction module based on phase-lock-loop (PLL) is used to improve the transfer performance in our passive scheme. In the proof experiment, the transfer stabilities of the implemented system are 2.86 × 10−14/1 s and 6.62 × 10−17/10 4 s over 80 km standard single mode fiber link. [ABSTRACT FROM AUTHOR]

We fabricate double-tapered optical fibre tips by the interfacial layer etching method. The optical fibre is first etched by means of meniscus-based etching to obtain one-tapered fibre tip, which is etched again by the interfacial layer between the etchant and the overlay to obtain a double-tapered tip. The formation mechanism of the second taper is analysed. The impacts of the interfacial layer etching time, HF concentration and the overlay on the second cone angle are discussed. The second cone angle can be controlled by the interfacial layer etching time and the overlay. But the HF concentration has few impacts on the second cone angle. The double-tapered fibre tips can be applied for the contactless trapping of particles. [ABSTRACT FROM AUTHOR]

In order to separate the multiplexed beams with different wavelengths in an all-fiber network, a novel concept of distinguishing different wavelengths by the orbital angular momentum (OAM) beams [i.e., L(topological charge) =1 and $L=-1$ ] based on the OAM fiber is proposed and investigated in the theory and experiments. Meanwhile, a new OAM fiber supporting the first order vector modes (i.e., TE0,1, HE2,1, and TM0,1) is also designed and fabricated. For the sake of verifying the feasibility of the proposed scheme, an experimental platform is anticipated and established. Bit error rates (BERs) and constellation diagrams are employed to evaluate the performance of the proposed schemes with respect to the transmission rate of data (V) and the difference of wavelength between the two input lasers. The simulated and measured results demonstrate that two different wavelengths (i.e., 1548 and 1545 nm) with the cycle of 14 and 10 nm can be distinguished though two OAM beams (i.e., $L=1$ and $L=-1$), respectively. The measured BERs and constellation diagrams with respect to data rates (V) depict that the performance of the proposed schemes degenerates with the increment of data rates (V) from 5 to 40 Gb/s. Similarly, the measured BERs and constellation diagrams with respect to the difference of wavelengths also demonstrate that the performance of the proposed scheme can be improved by increasing the difference of wavelengths from 1 to 4 nm. [ABSTRACT FROM AUTHOR]

The phenomenon of modal noise, which is typically undesired within fiber optic links, is exploited advantageously to characterize vertical cavity surface emitting lasers (VCSELs) operating in the first optical window (wavelength $\lambda \simeq 850$ nm), in terms of frequency chirping. The proposed method, which can be applied utilizing ordinary laboratory components and instrumentation, contributes to fill an existing gap. Indeed, the methods which are typically exploited to determine this undesired optical frequency modulation can be straightforwardly applied only to sources operating at wavelengths of 1310 and 1550 nm, while they become unpractical or even inapplicable at wavelengths of 850 nm. Through the proposed technique, the evaluation of chirp coefficient $M$ and phase difference $\psi $ between frequency and intensity modulation (or equivalently linewidth enhancement factor $\alpha $ and chirp scaling factor $\kappa $) of VCSELs can be performed. This allows the correct design of various types of fiber optic links, making possible to take advantage of these low-cost and low-consumption optical sources. [ABSTRACT FROM AUTHOR]

In this paper, we propose and experimentally demonstrate a tunable erbium-doped fiber laser (EDFL) with Sagnac interference loop with 45° angle shift spliced polarization maintaining fibers (PMFs). In the Sagnac loop, two PMFs with similar lengths. The Sagnac loop outputs a relatively complex interference spectrum since two beams transmitted in clockwise and counterclockwise encounter at the 3 dB coupler, interfere, and form two interference combs when the light transmitted in the Sagnac loop. The laser will excite and be stable when two interference lines in these two interference combs overlap together. Then by adjusting the polarization controller, the wide wavelength tuning is realized. Experimental results show that stable single wavelength laser can be realized in the wavelength range of 1585 nm–1604 nm under the pump power 157.1 mW. The side-mode suppression ratio is not less than 53.9 dB. The peak power fluctuation is less than 0.29 dB within 30 min monitor time and the side-mode suppression ratio is great than 57.49 dB when the pump power is to 222.7 mW. [ABSTRACT FROM AUTHOR]

A novel design of a polarization filter based on photonic crystal fiber (PCF) is proposed in this paper. With the introduction of a gold-coated air hole, the resonance strength is much stronger in y-polarized direction than in x-polarized direction at some particular wavelengths, which is due to the metal surface plasmon effects. At the wavelength of 1.31 μm, the loss of y-polarized mode is 2138.34 dB/cm while the loss is very low in x polarization. Furthermore, the loss peak can be flexibly adjusted from the wavelength of 1.26 to 1.56 μm by changing the thickness of a gold layer, and the loss in y polarization can be kept above 1200 dB/cm. The significant loss in y polarization makes this PCF a good candidate for developing a polarization filter with high performance. [ABSTRACT FROM AUTHOR]

Over the past several decades, the data-carrying capacity of a single optical fiber have been increased significantly by fully exploring and optimizing physical dimensions of the light. Generally there are five major candidates of dimensions, including time, wavelength, polarization, space and quadrature (phase and amplitude). Multi-dimension, utilizing more than two dimensions of the light simultaneously, is one of the essential characteristics of next generation optical communication systems. We review recent advances in transmission of multi-dimensional signals, and highlight innovative ways of exploring the polarization dimension to further increase the capacity or spectral efficiency of a single optical fiber, a so-called pseudo-polarization-division-multiplexing (PPDM) technique. Related demonstrations include non-orthogonal PDM, PPDM of three and four states (PPDM-3 and PPDM-4). Brief discussions on trends of multi-dimensional signal transmission technologies are also presented. [ABSTRACT FROM AUTHOR]

The results of international comparisons in the field of fiber-optic communication and information transmission systems, in particular, for the average power of optical radiation (COOMET PR-S6 and APMP PR-S2 projects) and chromatic dispersion in an optical fiber (EURAMET PR-S3 project), are considered. Data on comparisons as regards the length of the optical fiber (APMP PR-S8), polarization mode dispersion (COOMET PR-S9 project), and wavelength for fiber optics (COOMET PR-S8 project), all of which are now being performed, are presented. [ABSTRACT FROM AUTHOR]

We report a large mode area (LMA), Ge11.5As24Se64.5 six-fold symmetry quasi-periodic dual cladding leakage channel fiber (LCF) for supercontinuum generation (SCG) from 2 to 15~\mu \textm wavelengths. The proposed LMA fiber exhibits single-mode behavior by means of higher order mode delocalization for the entire wavelengths. Besides, the LCF possesses two zero dispersion wavelengths at 4.36 and 14.16~\mu \textm . Indeed, we numerically demonstrated the spectral broadening of continuum for the first time from 2 to 15~\mu \textm in the quasi-periodic dual cladding LCF for a length of 10 mm. It is observed that the red-shifted soliton at the centre wavelength of 9.42~\mu \textm obtain an energy of 0.164 nJ for a low input energy of 0.2 nJ. Further, the SCG in the proposed LCF attains a high conversion efficiency of 82 % at the solitonic spectrum and broadest spanning from 2 to 15~\mu \textm for the low input energy of 0.2 nJ. Thus, the proposed LCF-based SC source is the best choice for the applications, such as optical sensing, optical communication, food quality monitoring, and early cancer diagnostics. [ABSTRACT FROM PUBLISHER]

A mode-forming remote switch in multi-mode fiber distributing networks has been proposed. It can transmit the desired data to the desired port by adjusting transmitter signals. Feasibilities of the proposed scheme are confirmed by switching sub-carrier BPSK signal to the selected port. A graded-index multi-mode fiber link whose output is divided into two ports by a mode-dependent optical coupler, is used as mode-division multiplexing network. Its channel matrix is obtained by using MIMO processing technologies. Amplitudes and phases of the data are adjusted according to the channel matrix. The data is successfully switched to the desired port. Also, wavelength independences are clarified. [ABSTRACT FROM AUTHOR]

We propose and demonstrate a multi-channel SPR sensor based on the cascade application of the single-mode and multimode optical fiber. At this article, we studied the relationship between the gold film thickness and the sensing performance of the multimode fiber-based SPR sensor, the larger is the gold film thickness, the longer is the resonance wavelength, and the better is the sensitivity. We also studied the relationship between the grinding angle of the single mode optical fiber and the sensing performance of the single mode fiber-based SPR sensor, the larger is the grinding angle, the longer is the resonance wavelength, and the better is the sensitivity. Based on the above research, the reflected light of the single mode fiber-based SPR sensor is injected into the multimode fiber, and the multi-channel fiber-based SPR sensor is realized by fabricating transmitted SPR sensor on the multimode fiber. We realize the designable dynamic range adjustment by the cascade application of the single-mode and multimode optical fiber, and the sensitivity keeps constant. When the thickness of the gold film on the multimode fiber is 35 nm and the grinding angle of the single mode fiber is 16°(the gold film on the single mode fiber has a fixed thickness of 50 nm), the sensitivity of the two sensing zone on the multi-channel SPR sensor reach 2115 nm/RIU and 5212 nm/RIU respectively. [ABSTRACT FROM AUTHOR]

A long-range hybrid slot surface plasmon waveguiding structure that is capable of achieving ultra-small mode confinement and a long propagation distance simultaneously is proposed in this article. In comparison with the conventional long-range hybrid surface plasmon waveguide, the proposed waveguide can provide one order smaller mode area and a longer propagation distance by introducing a through-slot in the gap region. Meanwhile, the practical fabrication errors have little influence over mode properties of the waveguide. These results indicate that our designed waveguide can be a potential candidate for high-performance nanophotonic circuit and device. [ABSTRACT FROM AUTHOR]

We studied the reflection spectra of one-dimensional deformed periodic photonic crystal at the optical telecommunication frequency range, using the theoretical model based on the transfer matrix method. A broad reflection bands covering the 1.3 and 1.55 $$\upmu$$ m wavelength of telecommunication was obtained. The propagation of signals is forbidden for all incident angles and for both transverse electric and transverse magnetic polarizations. The deformation of the stack was introduced according to a power law with a coefficient k that represents the deformation degree. [ABSTRACT FROM AUTHOR]

A mathematical framework is presented to study the evolution of multi-point cumulants in nonlinear dispersive partial differential equations with random input data, based on the theory of weak wave turbulence (WWT). This framework is used to explain how energy is distributed among Fourier modes in the nonlinear Schrödinger equation. This is achieved by considering interactions among four Fourier modes and studying the role of the resonant, non-resonant, and trivial quartets in the dynamics. As an application, a power spectral density is suggested for calculating the interference power in dense wavelength-division multiplexed optical systems, based on the kinetic equation of the WWT. This power spectrum, termed the Kolmogorov-Zakharov (KZ) model, results in a better estimate of the signal spectrum in optical fiber, compared with the so-called Gaussian noise model. The KZ model is generalized to non-stationary inputs and multi-span optical systems. [ABSTRACT FROM PUBLISHER]

We propose and demonstrate a reflective-distributed surface plasmon resonance (SPR) sensor based on the twin-core fiber. Firstly, we study the effects of the fiber dual tapered (DT) probe grinding angle on the SPR dynamic range. The results show that for larger grinding angles, the resonance wavelength increases, resulting in a higher testing sensitivity. By using this method, we can make the sensor operate in an optimal waveband. Secondly, on the basis of the results above, we grind the DT probe to be an asymmetric wedge shape to configure two grinding angles (6° and 17°) to realize the distributed sensing. Results show that, with the refractive index detecting a range of 1.333–1.385, we can get two separated sensing zones, 591–715 nm and 729–966 nm, the testing sensitivity are 2385 nm/RIU and 4558 nm/RIU respectively. By using this method, we can detect multiple analytes in the same sensing area simultaneously, besides that we can also effectively compensate for the errors caused by background index interference, and the refractive index change resulting from the non-specific binding, or physical absorption and others. It worth to say that by using this method, we can adjust and control the resonance wavelength by changing the fiber grinding angle, while keeping the testing sensitivity is not reduced. For practical applications, this reflective distributed fiber-based sensor is much suitable for biochemical sensing, it has small size and can enter a small testing spaces (μm scale). The diameter of the twin-core fiber is the only 125 μm, which helps to be integrated into a micro-fluidic chip. In this paper, we integrate the fiber probe into an infusion needle to simulate blood vessels on-line monitoring. [ABSTRACT FROM AUTHOR]

In this paper, the filtering properties of photonic crystals (PCs) to perform narrow-channel transmission-type filters in second and third optical fiber telecommunication windows have been studied. Filtration of these zero dispersion and low-loss windows have simultaneously been established by utilizing of a triple-cavity transmission-type one-dimensional PC that provides perfect transmittances and narrow-channels at corresponding wavelengths. Such PC-based optical filter can be used in wavelength division multiplexing (WDM) optical communications systems. [ABSTRACT FROM AUTHOR]

To increase the transmission capacity of optical fiber transmission systems, we have developed a multiplexer- digital-to-analogue converter and an optical time-division multiplexing modulator, which respectively generate high-speed signals in the electronic and optical domains. With these devices, we can significantly increase the capacity per wavelength channel. [ABSTRACT FROM AUTHOR]

High-order quadrature amplitude modulation (QAM) is a promising approach for increasing the spectral efficiency of wavelength-division-multiplexing transmission, but its optical implementation is still challenging. We propose a customized IQ modulator for generating 64-QAM using equal-amplitude electrical binary drive signals and verify the operation through simulations. Using the embedded VOAs, the transmitter can be finely controlled and flexible for several modulation formats. [ABSTRACT FROM AUTHOR]

We investigate the wavelength dependence of stress-induced time of flight variations in graded-index multimode fibers (GI-MMFs) for wavelength λ = 1.26 μm ∼1.58 μm, theoretically and experimentally. Calculations were made based on simple equations using the refractive index of silica fibers. We measured the wavelength dependence of stress-induced time of flight variations by a newly proposed measurement method. We confirmed the similar wavelength dependence of GI-MMFs to that for standard single mode fibers (SSMF). However, the value of them is different. We compare the experimental and theoretical results for two types of fibers. The comparison indicates that the difference of stress-induced time of flight variations between two types of fibers is mainly due to the group velocity difference. We conclude that there is no significant difference of the photo-elastic constant between the measured SSMFs and GI-MMFs. Although many properties of GI-MMFs depended on the mode power distribution in general, we conclude the dependence of stress-induced time of flight variations on mode power distribution is small for the measured fibers. [ABSTRACT FROM AUTHOR]

An optimal gain-flattened lumped Raman fiber amplifier (L-RFA), which was designed by cascading different chalcogenide fiber, was proposed and numerically demonstrated. The As-S fiber and the As-Se fiber were pumped by laser with different wavelengths. By solving the equation of the L-RFA, the characteristics including the gain and gain flatness of L-RFA are investigated. The results show that the L-RFA pumped by dual wavelengths can provide gain-flattened band from 1544 to 1558.4 nm with 0.0293 km fiber. Moreover, the average gain and gain flatness are 26.083 and 0.173 dB, respectively. The factors which influenced the output characteristics of L-RFA were also analyzed. [ABSTRACT FROM AUTHOR]

This paper presents a teletraffic study that evaluates the benefits of a passive optical access network, fix/mobile, by multiplexing wavelength division (WDM-PON) in which it is appreciated the impact of including extra wavelengths channels for the transmission of multicast services versus the multicast transport service using replicated unicast connections. The conclusion is that under heavy bulk-data traffic, the nominal data rate and tolerated efficiency are defined by the maximum number of out-of-profile users permitted for every multicast solution. Specifically, for the high values of efficiency the channels of extra wavelength avoid the need of multicast wavelengths used only when there is a fraction (significantly small) of out-of-profile users (5%). [ABSTRACT FROM AUTHOR]

A novel photonic crystal fiber (PCF) based on a four-hole unit is proposed in order to meet the requirements of high birefringence, negative dispersion and confinement loss in fiber-optic communication. The proposed design has been simulated based on the full vector finite element method (FVFEM) and anisotropic perfectly matched layers (APML). Analysis results show that the proposed PCF can achieve a high birefringence to the order of 10 −2 at the wavelength of 1.55 μm, a large negative dispersion over a wide wavelength range and confinement losses lower than 10 −9 dB/m simultaneously, which has important applications in polarization-maintaining (PM) fibers, single-polarization single-mode (SPSM) fibers, dispersion compensation fibers and so on. [ABSTRACT FROM AUTHOR]

We present a method for transmitting 25-Gb/s optical nonreturn-to-zero signals at a wavelength of 1550nm over a 40-km single-mode fiber without any dispersion compensation methods. We propose optimized self-phase modulation by varying parameters of the fiber launching power and the extinction ratio of optical non-return to zero signals to overcome severe signal distortions by the chromatic dispersion effect. Using the optimization of the self-phase modulation effect, we were able to transmit 25-Gb/s optical nonreturn-to-zero signals over a 40-km single-mode fiber, which can be applicable to passive optical networks with a single wavelength channel and a high split ratio. We demonstrated that the self-phase modulation effect can be controlled by the extinction ratio and the fiber launching power. [ABSTRACT FROM AUTHOR]

Recently, metropolitan and access communication networks have markedly developed by utilizing a variety of technologies. Their bearer communication infrastructures will be mostly exploiting the optical transmission medium where wavelength division multiplexing techniques will play an important role. This contribution discusses the symmetric sharing of common optical network resources in wavelength and time domains. Wavelength-Division Multiplexed Passive Optical Networks (WDM-PON) attract considerable attention regarding the next generation of optical metropolitan and access networks. The main purpose of this contribution is presented by the analysis of possible scheduling of wavelengths for our novel hybrid network topologies considered for WDM-PON networks. This contribution briefly deploys adequate Dynamic Wavelength Allocation (DWA) algorithms for selected WDM-PON network designs with the provision of traffic protection when only passive optical components in remote nodes are utilized. The main part of this study is focused on the use of wavelength scheduling methods for selected WDM-PON network designs. For evaluation of offline and online wavelength scheduling for novel hybrid network topologies, a simulation model realized in the Matlab programming environment allows to analyze interactions between various metropolitan and access parts in the Optical Distribution Network (ODN) related to advanced WDM-PON network designs. Finally, wavelength scheduling methods are compared from a viewpoint of utilization in advanced WDM-PON networks designs. [ABSTRACT FROM AUTHOR]

A silicon nanowire embedded dual-core pentagonal photonic crystal fiber (PCF)-based polarization-independent wavelength splitter is proposed. The proposed PCF structure is analyzed using the finite element method. The wavelength splitting behavior of the PCF is investigated using the coupled-mode theory. The structural parameters of the PCF are optimized to achieve a coupling length ratio of 2. For the proposed PCF of length 102 μm, the cross-talk (CT) of −48.27 and −61.54 dB and CT bandwidth of 29.3 and 37.7 nm at 1.3 and 1.55 μm for X-polarization mode is achieved. However, the proposed PCF of length 115.5 μm attained the CT of −42.83 and −46.74 dB and CT bandwidth of 27.6 and 34.5 nm at 1.3 and 1.55 μm, respectively for Y-polarization mode. The polarization-independent wavelength splitter is achieved with the proposed PCF of length 108.75 μm. The proposed PCF-based wavelength splitter will be an inevitable candidate for integrated optical systems. [ABSTRACT FROM AUTHOR]

• Multiwavelength Tm-doped fiber laser based on the nonlinear polarization rotation effect is reported. • The switching of wavelength difference is realized in dual-wavelength operation. • The mechanism of multiwavelength output and wavelength difference switching is clarified. In this paper, we report on the characteristics of multiwavelength output and wavelength difference switching in a Tm-doped fiber laser based on the nonlinear polarization rotation effect. The multiwavelength output and wavelength difference switching were realized through joint action of nonuniform intensity-dependent loss caused by the nonlinear polarization rotation effect and the polarization controller intertwined with Tm-doped fiber. Under dual-wavelength state, one wavelength could be switched within wavelength intervals of 44.7, 58.0, 68.2, and 73.1 nm, and the position of the other wavelength nearly remained unchanged in the switching process. The fiber laser with switchable wavelength difference has a broad application prospect in laser space communication and optical fiber sensing. [ABSTRACT FROM AUTHOR]

We study the interaction properties of optical soliton pulses propagating in a two-channel wavelength-division multiplexed strongly dispersion managed communication system. We analyze the effects of third order dispersion, Raman scattering and self-steepening using an ordinary differential equations model obtained by a variational method applied to the Generalized Nonlinear Schrödinger Equation. The validity of the model is assessed against the integration of the full nonlinear partial differential equations. The variational equations are initially solved for a single pulse in order to identify the launching parameters for each pulse in the first DM cell of the system. One pulse per wavelength is then injected in the transmission link. We then systematically study the evolution of multiplexed soliton trains and analyse the transmission system in terms of residual frequency shifts and interchannel interactions as the map strength is varied, focusing on the ratio of dissimilar peak powers in a broad range of dispersion difference values, concluding that the transmission characteristics improve by using specific values of unequal energies and considering higher-order correction terms. The work presented is an extension of previous analysis where isolated intra-channel two-pulse interactions had been addressed considering pulses with dissimilar energies. [ABSTRACT FROM AUTHOR]

A new polarization rotator based on the silica photonic crystal fiber is proposed. The proposed polarization rotator photonic crystal fiber (PR-PCF) possesses a triangle jigsaw-shape core region. The full-vector finite-element method is used to analyze the phenomenon of polarization conversion between the quasi-TE and quasi-TM modes. Numerical simulations show that the wavelengths of 1.31 μm and 1.55 μm are converted with a nearly 100% polarization conversion ratio with their matched coupling length and has a relatively strong realistic fabrication tolerance −100 nm on the y axis and 50 nm on the x axis. The full vectorial finite difference beam propagation method is used to confirm the performance of the proposed PR-PCF. [ABSTRACT FROM AUTHOR]