Broadband Dispersion Compensation Research Articles

Broadband dispersion compensation and high birefringence photonic crystal fiber for CWDM/DWDM networks

In this study, we propose a new design based on photonic crystal fibers (PCFs) for broadband dispersion compensation in telecommunication networks. The proposed design has a hexagonal structure arrangement of air-holes rings of different diameters between the silica core and the cladding. The PCF properties like effective area, nonlinearity, dispersion slope, confinement loss, and birefringence are reported and discussed. For the best performance we present three designs A, B and C. Simulation results show that the three designs cover the six-telecommunication optical bands O-, E-, S-, C-, L- and U- bands (wavelengths ranging from 1260 to 1675 nm). Design A achieves a large negative dispersion value of about − 1716 ps/(nm.km) with relative dispersion slope equals to that of conventional single-mode optical fibers (SMFs) of about 0.0036 nm−1, which makes it very suitable for long-haul DWDM transmission systems. With a little modification in the core, designs B and C achieve much higher confinement ability and achieve a very large birefringence value for polarization mode dispersion and sensing applications. Design C is engineered to have exact opposite dispersion of SMF with zero dispersion at the wavelength 1310 nm, which makes it a promising design in CWDM transmission system. The numerical values have been investigated using the full vector finite element method.

Numerical analysis of microstructured optical fibers based on flint glass for ultra-high nonlinearity, low loss, and broadband dispersion compensation across telecom bands

This research investigates the potential of flint glass as a foundational material for photonic crystal configurations designed to achieve high nonlinear coefficients across various communication wavelengths. We explore dispersion management within telecom bands using flint glass-based micro-structured optical fibers, employing numerical analysis via the finite element method to assess optical properties. In this study, three different basic MOF structures (hexagonal, square, and octagonal) were created using flint glass background material rather of the commonly utilized fused silica material, and the numerically was assessed in contrast to prior studies and designs. Among the configurations studied, the octagonal arrangement (FGO-MOF) excels in dispersion compensation, achieving −136.6 ps/(nm.km) at 1.55 µm. Conversely, the hexagonal air hole ring cladding design (FGH-MOF) displays higher nonlinearity (770.5 W−1.km−1), a smaller effective area (1.115 µm2), and a high numerical aperture (0.6378). In contrast, the square air hole ring cladding optical fiber (FGS-MOF) exhibits low confinement loss (6.309 × 10−7 dB/cm) at 1.55 µm but with comparatively less favorable optical properties. Our study demonstrates that the hexagonal microstructured optical fiber with flint glass (FGH-MOF) offers superior performance in dispersion compensation, nonlinearity, and low loss within telecom bands. This finding suggests promising applications in high-bit-rate communication systems, biomedical sensing, and supercontinuum generation, presenting exciting avenues for further research and practical implementation.

Inverse Design of Broadband Dispersion Compensation Fiber Based on Deep Learning and Differential Evolution Algorithm

A Ge-doped dual-core dispersion compensation photonic crystal fiber (DC-DCPCF) is proposed. The small diameters of two layers’ air holes make DC-DCPCF form a dual-core structure, which is conducive to broadband dispersion compensation. Low Ge-doped silica as the only background material reduces the preparation difficulty and cost. It is inversely designed by using artificial neural network (ANN) combined with differential evolution algorithm (DE) to obtain target dispersion compensation. ANN replaces the finite element method to accomplish fast forward prediction of DC-DCPCF properties. DE solves the single solution problem of single or cascade network that makes it flexible and reproducible. The results demonstrate that the designed DC-DCPCF can not only compensate 45 and 25 times its length of Corning single-mode fiber 28 (SMF28) in S+C+L+U bands and E+S+C+L+U bands respectively, but also accurately compensate the residual dispersion with effective dispersion compensation being only +0.005∼+0.842ps/(nm·km) and −0.03∼+1.31ps/(nm·km), respectively. In addition, the kappa values of DCP-PCF are well matched with SMF28 in the broadband wavelength range. It takes only about 10 seconds to complete the inverse design of the target DC-DCPCF. It provides a design method for custom DC-DCPCF and an efficient inverse design solution for photonic automation in fiber optical communication systems.

Multiresonant metasurfaces for arbitrarily broad bandwidth pulse chirping and dispersion compensation

We show that ultrathin metasurfaces with a specific multiresonant response can enable simultaneously arbitrarily strong and arbitrarily broadband dispersion compensation, pulse (de)chirping, and compression or broadening. This breakthrough overcomes the fundamental limitations of both conventional nonresonant approaches (bulky) and modern singly resonant metasurfaces (narrowband) for quadratic phase manipulations of electromagnetic signals. The required nonuniform trains of resonances in the electric and magnetic sheet conductivities that completely control phase delay, group delay, and chirp are rigorously derived and the limitations imposed by fundamental physical constraints are thoroughly discussed. Subsequently, a practical, truncated approximation by finite sequences of physically realizable linear resonances is constructed and the associated error is quantified. By appropriate spectral ordering of the resonances, operation can be achieved either in transmission or reflection mode, enabling full space coverage. The proposed concept is not limited to dispersion compensation, but introduces a generic and powerful ultrathin platform for the spatiotemporal control of broadband real-world signals with a myriad of applications in modern optics, microwave photonics, radar, and communication systems.

A Highly Birefringent Negative Chromatic Dispersion Photonic Crystal Fibre for Long-haul Transmission: Design and Analysis

In this work, we report for the first time, a simplex index guiding circular PCF (CPCF) structure operating from 1350 nm to 1650 nm wavelength, which exhibits a highly negative dispersion of −13686.5 ps/(nm-km) at the telecommunication wavelength of 1.55 µm. The proposed CPCF exhibits a birefringence of 2.26×10-2, with a low confinement loss of 4.7×10-5 dB/km, which is suitable for ultra-high speed broadband dispersion compensation in long-distance transmission as well as supercontinuum generation, polarization maintenance, and sensing applications.

Numerical studying of broadband tunable dispersion compensation based on photonic crystal fiber

We propose a broadband tunable negative dispersion photonic crystal fiber (BT-ND-PCF) for dispersion compensation over the S + C + L wavelength bands. BT-ND-PCF is a dual-core structure in which air holes are arranged with a hexagonal lattice and temperature-sensitive liquid is infiltrated into the air holes of the fourth layer. The performance of BT-ND-PCF is numerically analyzed by the finite element method with an anisotropic perfect matching layer. The results show that BT-ND-PCF has a broadband negative dispersion coefficient of −1533.2 to −2836.4 ps / km / nm over the S + C + L wavelength bands, a dispersion coefficient of −2268.9 ps / km / nm at 1550 nm, and a kappa value of 287.9 nm at 1550 nm, which matches with Corning single-mode fiber 28 (SMF). The residual dispersion (RD) after compensating for the dispersion of 1 km SMF is in the range of −0.22 to +0.16 ps / nm. In addition, the dispersion coefficient is changed by 0.679 ps/km/nm per 1°C by controlling the temperature, which is conducive to the accurate compensation of RD. Due to its unique optical properties, BT-ND-PCF can be used in broadband dispersion compensation for dense wavelength division multiplexing optical fiber communication systems.

Sandwiched photonic crystal fiber for dispersion compensation over the S + C + L + U wavelength bands.

We numerically investigated a sandwiched photonic crystal fiber (S-PCF) based on triangular lattice air holes that can be used for broadband dispersion compensation. By adjusting two layers of air holes diameter in the cladding, the S-PCF performs a large negative dispersion curve that can compensate for the dispersion of a standard single-mode fiber (SMF). The kappa value of the proposed PCF is also consistent with that of the SMF at the wavelength of 1.55 µm. In addition, the dispersion compensation multiple reaches up to 25.37. We have successfully obtained an effective compensated dispersion with the value of -0.5 to +0.1ps/nm/km in the wavelength of 1.46-1.67 µm, which covers the S+C+L+U wavelength bands. Moreover, we considered the manufacturing tolerance of the dispersion and effective compensated dispersion with ±2% and ±5% variation.

High birefringence and broadband dispersion compensation photonic crystal fiber

Abstract We propose a perfectly square lattice photonic crystal fiber (PCF) which shows high birefringence and negative dispersion. To set up high asymmetry in the core, dual line imperfection is considered where the fill fraction ratio and defect air hole diameter exhibit significant impact on dispersion and birefringence. Numerical analyses of guiding properties of the proposed PCF are done using finite element method with perfectly matched layer boundary condition from 1.2 to 1.8 μm wavelength. The optimized square lattice PCF presents high birefringence of 2.48 × 10−2 and dispersion of −777.66 (ps/nm.km) at 1.55 μm wavelength. In addition, the proposed PCF offers ultra-low confinement and insertion loss at 1.55 μm wavelength. Moreover, −0.45 (ps/nm2.km) dispersion slope and 0.0045 nm−1 relative dispersion slope are observed at 1.55 μm wavelength. Additionally, the proposed PCF maintains dispersion and birefringence variation of ±30 (ps/nm.km) and ±0.00001 between 1.5 and 1.6 μm wavelength ranges, respectively. Furthermore, the proposed PCF shows high quality factor and low bit error rate at 10 dBm input power. We believe the proposed square lattice PCF can be deployed in wavelength division multiplexing based optical fiber transmission system for wide-band dispersion compensation.

Theoretical analysis of large negative dispersion photonic crystal fiber with small confinement loss.

Solid core circular and octagonal photonic crystal fibers (CPCF and OPCF) are proposed for analyzing different guiding properties such as dispersion, effective mode area, nonlinearity, and confinement loss from 0.8 to 2.6 µm wavelength. The proposed structures use three different types of background materials: SF10, BK7, and silica. Moreover, the fill fraction is varied by changing the diameter of the air hole where the lattice pitch is unchanged. The proposed PCFs show a high negative dispersion with low confinement loss and small effective mode area. In the proposed design, the finite element method with a perfectly matched layer absorbing boundary condition is used. At 1.8 µm wavelength with 0.6 fill fraction, the maximum negative dispersion of -922.5ps/(nm.km) is observed for CPCF when the background material is SF10. In addition, at this particular wavelength, the confinement loss is observed to be very small. Moreover, -560.12ps/(nm.km) dispersion is found for the similar condition at 1.55 µm wavelength. On the other hand, using BK7 as the background material, -706.77ps/(nm.km) dispersion is found at 1.55 µm wavelength for CPCF. Results also imply that CPCF shows better performance than OPCF for a wide wavelength range. Furthermore, at 1.55 µm wavelength, silica-based glass exhibits maximum dispersion, whereas increasing wavelength flint type glass shows the similar result. Analyzing different guiding properties of PCFs has significant impact on broadband dispersion compensation applications, especially using SF10.

A simple multifunctional broadband dispersion compensation and frequency conversion scheme by utilizing a polarization division multiplexing dual-parallel Mach-Zehnder modulator

A simple broadband dispersion compensation and frequency conversion scheme is proposed, which based on a typical commercial polarization division multiplexing dual-parallel Mach-Zehnder modulator (PDM-DPMZM). It has two operating modes that you can decide if you need frequency conversion while implementing dispersion compensation. Each polarization of the PDM-DPMZM can achieve single-frequency dispersion compensation, and is easy to complement each other. It means that the power fading in one polarization can be cancelled by the other one, and vice versa. Hence, the RF signal power levels are all fully compensated within a large frequency range. No matter which operating modes, simulation results show that the power of the received signal is almost not affected by the frequency of the transmitted signal and the length of the fiber, and the SFDR is improved by about 15 dB over the dispersion link. The spectrum of the received GHz-level broadband signal has hardly changed. A 100 Mbaud RF vector signals with different frequency or input power are successfully transmitted with good constellation diagrams and low EVMs.

Active Terahertz Anisotropy and Dispersion Engineering Based on Dual-frequency Liquid Crystal and Dielectric Metasurface

Active broadband terahertz (THz) phase difference and its dispersion engineering based on the combination of dielectric metasurface and dual-frequency liquid crystal (DFLC) has been demonstrated, which can realize broadband achromatic wave plates and active manipulation by tuning the alternating ( AC ) frequency of electric field from 1 to 90 kHz. The artificial anisotropy of the dielectric metasurface is introduced to offset the tunable natural birefringence of the DFLC, so that the effective tuning range of the composite metadevice has been significantly improved, across from 0 to 1.0π, thus realizing the conversion from linear polarization (LP) light to arbitrarily polarized light. Moreover, a negative-dispersion phase difference of the dielectric metasurface can be achieved in the range of 0.69–1.4 THz by designing proper geometric parameters, which can be compensated with the positive-dispersion phase difference of DFLC to realize an achromatic device with broadband zero dispersion. The results show that the device can be tuned from OFF state without polarization conversion to a half-wave plate in 0.97–1.3 THz with the polarization conversion ratio (PCR) of over 97%, or to a quarter-wave plate in 0.67–1.3 THz with the PCR of over 96% by changing the AC frequency of the electric field. The active AC frequency tuning characteristics, anisotropic enhancement and broadband dispersion compensation show its great potential in THz application systems.

Optimization of silica glass capillary and rods drawing process.

Diameter fluctuations of silica glass rods and capillaries, during drawing process have been studied. We investigated an influence of drawing conditions on the quality of capillaries and rods. We fabricated two preforms made from different quality material. Fabricated preforms were used to draw microstructured fibers. Full Text: PDF ReferencesS. Habib et al., "Broadband dispersion compensation of conventional single mode fibers using microstructure optical fibers", Int. J. Lig. Opt. 124, 3851-3855 (2013) CrossRef A. Ziolowicz et al. "Overcoming the capacity crunch: ITU-T G.657.B3 compatible 7-core and 19-core hole-assisted fibers", Proc SPIE 10130, 101300C (2017) CrossRef T.M. Monro et al. "Sensing with microstructured optical fibres", Meas. Sci. Technol. 12, 854-858 (2001) CrossRef G. Statkiewicz-Barabach et al.,"Hydrostatic Pressure and Temperature Measurements Using an In-Line Mach-Zehnder Interferometer Based on a Two-Mode Highly Birefringent Microstructured Fiber", Sensors 2017, 17, 1648 (2017) CrossRef T. Yoon, M. Bajcsy, "Laser-cooled cesium atoms confined with a magic-wavelength dipole trap inside a hollow-core photonic-bandgap fiber", Phys. Rev. A 99, 023415 (2019) CrossRef A.N. Ghosh et al., "Supercontinuum generation in heavy-metal oxide glass based suspended-core photonic crystal fibers", J. Opt. Soc. Am. B 35, 2311-2316 (2018) CrossRef G. Wójcik et al. "Microbending losses in optical fibers with different cross-sections", Proc. SPIE 10830, 108300H (2018) CrossRef F. Xu, Selected topics on optical fiber technology and applications (IntechOpen 2018) CrossRef

Ultra-high negative dispersion and nonlinearity based single mode photonic crystal fiber: design and analysis

In this article, we have proposed a large negative dispersion coefficient and highly nonlinear polarization maintaining single mode square photonic crystal fiber. The proposed design is extremely attractive for compensation of chromatic dispersion of − 1052.60 ps/(nm km) to − 2421.90 ps/(nm km) around 1340–1640 nm wavelength band. Guiding characteristics are investigated applying finite element method containing perfectly matched layer boundary condition. Simulation outcomes ensure the possibility of large negative dispersion coefficient and low confinement loss of − 2015.30 ps/(nm km) and 3.41 × 101 dB/m respectively, at 1550 nm wavelength. The proposed fiber also exhibits highly nonlinear coefficient of 99.73 W−1 km−1 at the same wavelength. Moreover, V parameter assures the single mode operation of the structured fiber over the whole band of interest. The structural diameter variation of ± 2% over the optimum value is simulated and reported to explore the practical feasibility. Besides, effective area is also presented and explained. From overall investigations, it can be reported that the proposed fiber will be an attractive candidate in high-speed transmission system for broadband dispersion compensation, nonlinear optics and sensing applications as well.

Properties of a novel hybrid hollow core photonic crystal fiber

Abstract We present a novel hybrid hollow-core photonic crystal fiber, which can confine and guide light in subwavelength-diameter air holes of core. The propagation mechanism of low-refractive-index hole is studied by evanescent field coupling and electromagnetic theory of optical waveguide transmission. The unique transmission characteristics in the novel fiber with new propagation mechanism are shown. The evanescent-field power fraction in the core holes can be changed flexibly between 10% and 50%. The confinement loss is very low in the broadband wavelength range 1–1.8 μm, which is not limited by surface modes and photonic bandgap effect appearing in hollow-core photonic bandgap fibers. The excellent characteristics of matching mode area, high birefringence, single polarization and single mode in hollow-core fiber are obtained. The two-zero dispersion, broadband flattened dispersion and dispersion compensation properties of hollow-core fiber are also presented. The novel hybrid photonic crystal fiber has the characteristics of solid core fibers and is suitable for the application as hollow core fibers.

Modelling the broadband mid-infrared dispersion compensator with hybrid silicon and lithium niobate nanowire

The broadband dispersion compensator plays an important role for the light transmission of ultrashort pulses. Inspired by the requirement for a compact, tunable dispersion compensator operating in the mid-infrared spectral range, we proposed a compact dispersion compensator with hybrid silicon and lithium niobate nanowire configuration and investigated its group-velocity dispersion characteristics numerically. The results show that the tailored hybrid waveguide can exhibit group velocity dispersion of up to 105 ps2·km−1 in the 2~5 μm spectral range. In addition, the dispersion can be tuned via the applied bias field by the aid of the excellent electro-optical performance of the host material, lithium niobate. This work may provide some guidelines for designing broadband dispersion compensators and make an inroad for miniaturized functional optoelectronic devices.

Hybrid grating–prism dispersion eraser

A hybrid grating–prism dispersion eraser is proposed to achieve broadband dispersion compensation. A ray-tracing model is built up for its phase spectrum and derivatives. The numerical calculation shows that the eraser can compensate dispersion up to fourth-order. When it is used in chirped-pulse amplifiers, it can obtain aberration-free phase with above 120 nm bandwidth at 0.8μm central wavelength and support near-Fourier-transform-limited femtosecond pulses output.

Highly birefringent, highly negative dispersion compensating photonic crystal fiber.

A triangular lattice dispersion compensating photonic crystal fiber is presented in this paper. The fiber produces high birefringence and operates at fundamental mode only. The full vector finite element method with a perfectly matched absorbing layer boundary condition is applied to investigate the guiding properties of the proposed fiber. The designed fiber demonstrates that it is possible to obtain a very large negative dispersion of -9486.1 ps/(nm·km) at 1550nm wavelength with a negative dispersion more than -7000 ps/(nm·km) over the entire C-band (1530-1565nm), which is suitable for broadband dispersion compensation. The birefringence is about 4.13×10-2 at 1550nm wavelength, which is also very high. All these properties make this fiber very suitable in the area of broadband dispersion compensation and polarization-maintaining applications.

Proposed Square Lattice Photonic Crystal Fiber for Extremely High Nonlinearity, Birefringence and Ultra-High Negative Dispersion Compensation

Abstract A photonic crystal fiber in square lattice architecture is numerically investigated and proposed for broadband dispersion compensation in optical transmission system. Simulation results reveal that it is possible to obtain an ultra-high negative dispersion of about −571.7 to −1889.7 (ps/nm.km) in the wavelength range of 1340 nm to 1640 nm. Experimentally it is demonstrated that the design fiber covers a high birefringence of order 4.74×10‒3 at the wavelength of 1550 nm. Here, numerical investigation of guiding properties and geometrical properties of the proposed PCF are conducted using the finite element method (FEM) with perfectly match layers. Moreover, it is established more firmly that the proposed fiber successfully compensates the chromatic dispersion of standard single mode in entire band of interest. Our result is attractive due to successfully achieve ultra-high negative dispersion that is more promisor than the prior best results.

A solid silica core based non-linear hybrid PCF with low confinement loss

This paper aims to analyze solid silica core based Photonic Crystal Fibre (PCF). The proposed structures consists of three inner layers of hexagonal shaped air holes and four outer layers of circular shaped holes and compare it with oval shaped structure. The broadband dispersion compensation and confinement loss covering the O, E, S, C and L bands and observed zero and negative dispersion in O and E band also very low confinement loss in all bands. The diameter of air holes is varied to generate flattened dispersion characteristics for the hybrid cladding PCF structure. Our purpose is to attain high non-linearity along with low confinement loss of two layered photonic crystal fibre for different air fill fraction d/Λ (0.65–0.95) values. Also, it is shown that the non-linear coefficient magnifies with the decreasing wavelength in PCF and the confinement losses are less than 0.001dB/km in the O-E-S-C-L wavelength range from (1.2 to 1.6) μm.

Broadband Dispersion Compensation Technology in High Speed Optical Fiber Communication Systems

Broadband Dispersion Compensation Technology in High Speed Optical Fiber Communication Systems