Residual Dispersion Compensation Research Articles

Residual dispersion compensation photonic crystal fiber based on simulated annealing algorithm and Livelink data interaction

An octagonal photonic crystal fiber (O-PCF) structure with equal air hole diameter of the cladding is proposed for residual dispersion compensation, and a high refractive index material SF57 is introduced in the core region to make it have the advantages of high negative dispersion, low attenuation loss, low fabrication difficulty. Due to the symmetric structure, no additional polarization control is required in the dispersion compensation process, which further reduces the production cost. Using Livelink data interaction not only accelerates the modeling of O-PCF, but also enables the effective refractive index of HE11 to be unattended continuously searched. Furthermore, simulated annealing algorithm is used to reverse design the structural parameters of cladding air hole diameter and central solid hole diameter. The results show that, based on the simulated annealing algorithm interacting with Livelink data, the optimize efficiency, design accuracy and dispersion characteristics are improved. The ultra-flat high negative dispersion O-PCF can be reverse designed in the S + C + L and S + C + L + U bands which shows the average dispersion of −847.34 ps/(nm·km) and −752.90 ps/(nm·km) with the absolute dispersion of only ±7.25 ps/(nm·km) and ±10.28 ps/(nm·km), respectively. The designed RDCF is tolerant to ±1% and ±2% variation of the central solid hole diameter and the cladding air hole diameter during fabrication, respectively. The combination of simulated annealing algorithm and Livelink data interaction provides an efficient method for reverse design of PCF.

A comprehensive study of large negative dispersion and highly nonlinear perforated core PCF: theoretical insight

A photonic crystal fiber (PCF) containing circularly organized square-shaped air holes in the cladding region is investigated. The fiber core is perforated with four circular air-filled holes to instate high nonlinearity and large negative dispersion. The numerical analysis is done with a finite element method based COMSOL Multiphysics tool to investigate different optical properties of the propounded PCF. The simulation outcome verifies a high nonlinear coefficient value of 85 W−1 Km−1 at telecommunication window 1.55 μm which is, the highest ever achieved value on comparing with the other existing literature without using any nonlinear materials or liquids to the best of the authors’ knowledge. In parallel, the large negative value of dispersion −597 ps nm−1 km−1 is achieved for S/Λ equals 0.70 at the same communication window. However, the highest achieved nonlinearity and negative dispersion are 300 W−1 Km−1 and −1689 ps/nm/km. Moreover, birefringence, numerical aperture, and propagation loss are also measured as 2.40 × 10−3, 0.59, and 4.12 × 10−11 dB m−1 respectively along with an extremely high core power fraction of 99.98%. Hence, the propounded PCF is suitable for residual dispersion compensation, supercontinuum generation, and high bitrate transmission.

A squeezed photonic crystal fiber for residual dispersion compensation with high birefringence over S+C+L+U wavelength bands

A squeezed triangular lattice photonic crystal fiber (PCF) composed of elliptical air holes is presented in this paper. Full vector finite element method (FEM) is used to investigate the guiding property. By adjusting the size of air holes in cladding, the fiber offers a flat negative dispersion of -1343.46 ± 6.74 ps/(nm.km) over the wavelength bands of S+C+L+U. The birefringence can be on the order of 10−2 which reaches up to 3.72×10−2 at the wavelength of 1.55μm. The proposed PCF may show some important applications in residual dispersion compensation and polarization maintaining fibers.

Modified Octagonal Photonic Crystal Fiber for Residual Dispersion Compensation over Telecommunication Bands

Modified Octagonal Photonic Crystal Fiber for Residual Dispersion Compensation over Telecommunication Bands

Highly birefringent large negative dispersion-flattened photonic crystal fibre for broadband residual dispersion compensation

A triangular lattice photonic crystal fibre is presented in this paper for residual dispersion compensation. The fibre exhibits a flattened negative dispersion of −992.01 ± 6.93 ps/(nm-km) over S+C+L wavelength bands and −995.83 ± 0.42 ps/(nm-km) over C-band. The birefringence is about 4.4 × 10−2 at the excitation wavelength of 1550 nm which is also very high. Full vector finite element method (FEM) with a perfectly matched absorbing layer (PML) boundary condition is applied to numerically investigate the guiding properties of this PCF. The fibre operates at fundamental mode only. All these properties endorse this fibre as a suitable candidate for compensating residual dispersion and polarization maintaining applications.

Analytical Analysis of Residual Chromatic Dispersion and Self-Phase Modulation Optimal Compensation in the Fractional Domain

We present an analytical expression of residual chromatic dispersion and self-phase modulation optimal compensation with a chirped Gaussian pulse in the fractional domain. The accuracy of the expression is confirmed by the simulation platform, which is based on the split-step Fourier method. Moreover, the simulation of a 28-GBd RZ-DQPSK optical fiber communication system is carried out to verify the correctness when the transmission distance is less than 800 km in a standard single-mode fiber and non-zero dispersion-shifted fiber.

Design and Comparison of SF57 Over SiO2 on Same Structured PCF for Residual Dispersion Compensation

Two square photonic crystal fibers (SPCFs), one made of silica (SiO2) and the other made of high index lead silicate soft glass (SF57), are numerically analyzed, compared, and proposed in this paper. Both designs of SPCFs show very high negative and ultraflattened chromatic dispersion with very low variation of dispersion (ΔD). P-1 offers −650(±6) ps/(nm.km) for the wavelength range of $\text{1.46} \rightarrow \text{1.63}\; \mu \text{m}$ and bandwidth $(\text{BW}) = \text{170}\; \text{nm}$ and P-2 offers −693(±4) ps/(nm.km) for the wavelength range of $\text{1.45} \rightarrow \text{1.68}\; \mu \text{m}$ $(\text{BW}= \text{230}\;\text{ nm)}$ with average high birefringence of the order of 10–2. The proposed designs can be suitable for residual dispersion compensation while maintaining polarization due to having the properties of high negative flattened chromatic dispersion with high birefringence. The influence of changing the structural parameters up to ±0.02 $\mu$ m are also examined for ensuring the flatness of the property of chromatic dispersion within the acceptable level.

A Polarization Maintaining Single-Mode Photonic Crystal Fiber for Residual Dispersion Compensation

A single-mode octagonal photonic crystal fiber (OPCF) is proposed to simultaneously achieve high birefringence and ultra-flattened ultra-high negative dispersion. Simulation results demonstrate that by introducing an elliptical air hole in the center of the core, it is possible to obtain a large average dispersion of −608.93 ps/nm/km with an absolute dispersion variation of −12.7 ps/nm/km over 1.46–1.625 $\mu \text{m}$ wavelength bands for fundamental slow-axis mode. Besides, with optimal design parameters, a high birefringence of $1.81\times 10^{\mathrm {-2}}$ and a very low confinement loss of 0.04 dB/km are achieved at 1.55 $\mu \text{m}$ . The proposed OPCF can be used in cost-effective residual dispersion compensation and optical sensors.

A new photonic crystal fiber design on the high negative ultra-flattened dispersion for both X and Y polarization modes

Analysis of numerical design and properties of a new silica based photonic crystal fiber (PCF) are proposed in this manuscript. The design performs ultra-flattened negative chromatic dispersion (UNCD) in the optical windows 2nd and 3rd involving O to U bands in the infrared (IF) portion. The guiding properties are observed by employing a circular perfectly matched layer (PML) boundary through the finite-element method (FEM). The proposed design is compatible for the application of residual dispersion compensation (RDC) as it grants negative dispersion (ND) and very low scale dispersion variation (ΔD) of −(253.5±2.5) and −(292±2)ps/nm/km respectively for both X and Y polarization modes within the wavelength boundary of 1.25⟷to1.7μm (450-nm band). Moreover, ±10% alteration in the optimum parameters (OP) is also studied to assess the responsiveness of the dispersion characteristics.

Management of residual dispersion of an optical transmission system using octagonal photonic crystal fiber

An octagonal photonic crystal fiber (O-PCF) for numerical structure design and analysis of some particular properties are presented in this paper. The proposed design is suitable for residual dispersion compensation (RDC) with polarization maintaining (PM) applications as it offers extremely high-negative flattened average chromatic dispersion (DT) and absolute dispersion variation (ΔD) of around −(708±10) ps nm−1 km−1 and average high birefringence (B) of the order 10−2 for the wavelength limits of 1.46 to 1.67 μm (bandwidth of 210 nm that covers S+C+L+U bands in the infrared region of the optical third window). In addition, it exhibits very low confinement loss of 10−3.5 to 10−2.5 dB/m for that bandwidth. Moreover, to evaluate the sensitivity of the fiber properties (DT and B) during fabrication, ±0.02 μm variation in the optimum parameters is also studied.

Ultra-flattened negative dispersion for residual dispersion compensation using soft glass equiangular spiral photonic crystal fiber

We present a numerical investigation of an equiangular spiral photonic crystal fibre (ES-PCF) in soft glass for negative flattened dispersion and ultra-high birefringence. An accurate numerical approach based on finite element method is used for the simulation of the proposed structure. It is demonstrated that it is possible to obtain average negative dispersion of –526.99 ps/nm/km over 1.05–1.70 μm wavelength range with dispersion variation of 3.7 ps/nm/km. The proposed ES-PCF also offers high birefringence of 0.0226 at the excitation wavelength of 1.55 μm. The results here show that the idea of using the proposed fibre can be potential means of effectively directing for residual dispersion compensation, fibre sensor design, long distance data transmission system and so forth.

Characterization of Hexagonal Photonic Crystal Fiber for Zero Flattened Dispersion with Lower Confinement Loss and Residual Dispersion Compensation Over 500 nm Wavelength Bandwidth

Design methodology and characteristics analysis of a hexagonal photonic crystal fiber (H-PCF) is presented in this paper. Here, chromatic dispersion, effective area and confinement loss are analyzed for 1.00 to 2.10 μm wavelength range. The PCF is simulated by finite element method (FEM) with perfectly matched layers (PML). Hexagonal PCF with five rings of air holes for near zero ultra-flattened dispersion over 1100 to 1600 nm wavelength range is shown. The special property of proposed PCF is the design simplicity with near zero ultra-flattened dispersion, which is much needed in wavelength division multiplexing (WDM) applications. According to simulation work it is shown that, the designed microstructure optical fiber (MOF) shows near zero ultra-flattened dispersion of 0±1.00 ps/(nm.km), nonlinearity of 12.15 W -1 km -1 and confinement loss less than 10 -2 dB/km at the operating wavelength of 1550 nm.

Ultraflattened high negative chromatic dispersion over O+E+S+C+L+U bands of a microstructured optical fiber

This paper presents a large negative flattened dispersion with high birefringence for a very wide wavelength range by designing a new high index lead silicate (SF57) soft glass equiangular decagonal spiral microstructured optical fiber (DS-MOF). The bandwidth supports the second and third windows covering the O+E+S+C+L+U bands in the infrared region. The guiding properties of the DS-MOF are investigated by the finite-element method with a perfectly matched layer boundary. The proposed design is a suitable candidate for the application of residual dispersion compensation with maintaining polarization characteristics since it offers a high negative flattened dispersion of −(453 ± 7) ps⋅nm −1 km −1 with a high birefringence of the order 10 −2 for the wide wavelength range of 1.15 to 1.75 μ m. The DS-MOF has some circular air holes that make the fabrication process simple. In addition, the effects of changing the structural parameters by up to ±4% are also analyzed to ensure the accuracy during the fabrication process.

Design of a pentagonal photonic crystal fiber with high birefringence and large flattened negative dispersion.

Novel pentagonal photonic crystal fiber with high birefringence, large flattened negative dispersion, and high nonlinearity is proposed. The dispersion and birefringence properties of this structure are simulated and analyzed numerically based on the full vector finite element method (FEM). Numerical results indicate that the fiber obtains a large average dispersion of -611.9 ps/nm/km over 1,460-1,625nm and -474 ps/nm/km over 1425-1675nm wavelength bands for two kinds of optimized designs, respectively. In addition, the proposed PCF shows a high birefringence of 1.67×10-2 and 1.75×10-2 at the operating wavelength of 1550nm. Moreover, the influence of the possible variation in the parameters during the fabrication process on the dispersion and birefringence properties is studied. The proposed PCF would have important applications in polarization maintaining transmission systems, residual dispersion compensation, supercontinuum generation, and the design of widely tunable wavelength converters based on four-wave mixing.

Design and Characterization of Highly Birefringent Residual Dispersion Compensating Photonic Crystal Fiber

A residual dispersion compensating octagonal photonic crystal fiber (OPCF), with an elliptical array of circular air-holes in the fiber core region, is proposed. The full-vector finite-element method with perfectly matched layer boundary is used as the analysis tool. It is demonstrated that it is possible to obtain large average negative dispersion of -562.52 ps/(nm · km) over 240 nm and -369.10 ps/(nm · km) over 630 nm wavelength bands for the fast and the slow axis, respectively. In addition to large negative dispersion, ultra-high birefringence, high nonlinearity, and zero-dispersion wavelengths with low confinement loss are also warranted. The proposed OPCFs would be a promising candidate for residual dispersion compensation, supercontinuum generation, and other applications.

Proposal for highly residual dispersion compensating defected core decagonal photonic crystal fiber over S+C+L+U wavelength bands

A defected core decagonal photonic crystal fiber is designed and numerically optimized to obtain its residual chromatic dispersion compensation in the wavelength range of 1460 to 1675 nm i.e., over S+C+L+U wavelength bands having an average dispersion of about −390 ps/(nm km) with a dispersion variation of 7 ps/(nm km). The designed fiber, with a flattened dispersion profile, has four rings of holes in the cladding region, which results in low confinement loss and small effective mode area at wavelength 1550 nm. For residual chromatic dispersion compensation, the proposed fiber can be used in wavelength division multiplexing optical fiber data communication systems.

Residual dispersion compensation over the S + C + L + U wavelength bands using highly birefringent octagonal photonic crystal fiber.

An octagonal photonic crystal fiber (PCF) with an elliptical shape in the center core is numerically investigated for residual dispersion compensation in the wavelength range 1460-1675 nm. The designed fiber exhibits flattened negative dispersion over the S + C + L + U wavelength bands and an average dispersion of -465.5 ps/(nm·km) with an absolute dispersion variation of 10.5 ps/(nm·km). In addition, the proposed PCF shows a high birefringence of 2.68×10(-2) at the operating wavelength 1550 nm, which meets the requirement of high birefringence. Moreover, the variation of two air holes in the first ring up to 5% ensures an average dispersion of -491.5 ps/(nm·km) with a dispersion variation of 13 ps/(nm·km), and birefringence reaches up to 3×10(-2). Furthermore, to evaluate the sensitivity of the fiber dispersion properties, ±5% variation in the optimum parameters is studied.

A single mode ultra flat high negative residual dispersion compensating photonic crystal fiber

In this paper, a single mode photonic crystal fiber based on hexagonal architecture is numerically demonstrated for the purpose of residual dispersion compensation in the wavelength range of 980–1580nm. The designed fiber offers ultraflattened negative dispersion in the near-infrared to most widely used S to L wavelength bands and average dispersion of about −138ps/(nmkm) with an absolute dispersion variation of 12ps/(nmkm). Besides, the proposed fiber successfully operates as a single mode in the entire band of interest. Moreover, to check the dispersion accuracy, sensitivity of the fiber dispersion properties to a ±1–5% variation in the optimum parameters is studied for practical conditions.

Design of polarization-maintaining photonic crystal fibre for dispersion compensation over the E+S+C+L telecom bands

We investigate numerically a defected-core hybrid photonic crystal fibre (H-PCF) with a circular core and a rectangular-shaped cladding, which is designed for compensation of residual dispersion over a wide wavelength range. Our simulation results testify that this H-PCF exhibits a large negative dispersion (- 868 ps/(nm km)) over the E+S+C+L telecommunication bands, with the relative dispersion slope perfectly matching that of a single-mode fibre at the operating wavelength 1550 nm. The H-PCF reveals the birefringence 1.06×10 -2 at the operating wavelength. In order to evaluate the sensitivity of optical properties of our H-PCF, we study the effect of variations of its parameters as large as ±2% from their optimal values. Due to its specific characteristics, the H-PCF suggested in this work can be considered as an excellent candidate for compensating dispersion, maintaining a single polarization in the optical fibre transmission systems, and numerous optical sensing applications.

Tailoring polarization maintaining broadband residual dispersion compensating octagonal photonic crystal fibers

We present a residual dispersion compensating highly birefrin- gent photonic crystal fiber (PCF) based on an octagonal structure for broadband dispersion compensation in the wavelength range 1460- 1625 nm. The finite element method with perfectly matched boundary con- dition is used as the numerical design tool. It has been shown theoretically that it is possible to obtain a negative dispersion coefficient of about −418 to −775 ps∕nm∕km over the S-, C-, and L-bands, relative dispersion slope (RDS) close to that of single mode fiber (SMF) of about 0.0036 nm −1 at 1550 nm. According to the simulation, birefringence of 2 × 10 −2 is obtained at 1550-nm wavelength. The variation of structural parameters is also studied to evaluate the tolerance of the fabrication. The proposed octago- nal PCF can be a potential candidate for residual dispersion compensation as well as maintaining single polarization in optical fiber transmission sys- tem. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE) (DOI: 10.1117/1.OE .52.11.116111)