M. Samiul Habib

An Elliptical-Shaped Core Residual Dispersion Compensating Octagonal Photonic Crystal Fiber

A residual dispersion compensating photonic crystal fiber (PCF) is proposed having elliptical-shaped core and octagonal structure with isosceles triangular-latticed cladding. The finite element method with circular perfectly matched layer is used to investigate the guiding properties. It is demonstrated that it is possible to obtain average dispersion of -544.7 ps/(nm.km) in a wavelength range of 1.46-1.70 μm with ultrahigh birefringence of 2.2 × 10-2 and nonlinear coefficient of 52.7 W-1km-1 at a 1.55-μm wavelength. Besides, the proposed PCF shows confinement losses <;42.4 and 0.012 dB/km for five and eight rings, respectively.

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 defected core highly birefringent dispersion compensating photonic crystal fiber

In this paper we propose a defected core Photonic Crystal Fiber (PCF) having circular lattice that ensures Residual Dispersion Slope (RDS) matched negative dispersion covering S+C+L communication bands with high birefringence for sensing purpose. The results show that this PCF has an average value of negative dispersion of -331 ps/nm-km & offers high birefringence of 2.75×10-2 with relative dispersion slope (RDS) perfectly matched to that of single mode fiber of about 0.0036 nm-1 at the wavelength 1550 nm. Due to its optical properties, the proposed fiber can be considered as an excellent candidate for sensing applications by maintaining single polarization along with dispersion compensation in optical fiber transmission system.

Design of highly birefringent holey fibers with near-zero ultra-flattened chromatic dispersion and ultralow confinement loss

We present a holey fiber (HF) with elliptical air-holes located in the center core area that ensures high birefringence, near-zero ultra-flattened chromatic dispersion and very low confinement losses in a wide wavelength range. The finite element method with perfectly matched boundary layer is used to investigate the guiding properties. It is demonstrated that it is possible to design a low-loss dispersion-flattened HF with a high birefringence of 0.0033 at a 1.55 µm wavelength. According to simulation, near-zero ultra-flattened dispersion of 0 ± 0.5 ps/nm/km is obtained in a 1.25 to 1.65 µm wavelength range with low confinement losses of 0.0008 dB/km in the entire band of interest.

A new circular photonic crystal fiber for effective dispersion compensation over E to L wavelength bands

This paper presents a new circular photonic crystal fiber (C-PCF) for effective dispersion compensation covering E to L wavelength bands ranging from 1360-1625 nm. To investigate its guiding properties, finite element method (FEM) with a perfectly matched layer absorbing boundary condition is used. From our numerical simulation, it is found that the designed C-PCF simultaneously shows a large negative dispersion of about -248.65 to -1069 ps/(nm.km) over E to L wavelength bands and a relative dispersion slope (RDS) exactly equal to that of a single mode fiber (SMF) at 1.55 µm wavelength. It is also found that residual dispersion after compesating 40 km long SMF is within ±62 ps/nm which ensures application of C-PCF in high speed WDM system. Besides, dispersion slope, slope compensation ratio, effective area and confinement loss of the proposed C-PCF are also evaluated and discussed.

Dispersion and confinement loss control with decagonal photonic crystal fibers for wideband transmission systems

In this paper, we propose and demonstrate a simple photonic crystal fiber (PCF) based on decagonal cladding structure for simultaneous control of dispersion and leakage properties restoring the design simplicity. Simulation results show that decagonal photonic crystal fibers with five rings can assume ultra-flattened dispersion of 0 ± 0.6 ps/nm/km in the wavelength range of 1.30 to 1.60 μm with low confinement losses less than 10-7 dB/km at telecom window.

Design of a square lattice photonic crystal fiber for dispersion compensation over telecom bands

In this paper, we numerically demonstrate a large negative dispersion with highly birefringent square lattice photonic crystal fiber (SLPCF) in the entire telecom wavelength bands. Finite element method with perfectly matched layer boundary condition is used to evaluate the modal properties of the fiber. Numerical results reveal that it is possible to obtain a large negative dispersion coefficient of -897 ps/(nm.km), a relative dispersion slope (RDS) close to that of single mode fiber (SMF) of about 0.0036 nm-1 and birefringence of the order 1.34×10-2 at 1.55 μm. To evaluate the tolerance of fabrication variation of structural parameters from their optimum value is carried out.

Low dispersion nonlinear polarization maintaining Photonic Crystal Fiber using hybrid cladding

This paper presents and explores a new design hybrid cladding of nonlinear Photonic Crystal Fiber (PCF) with both very low dispersion and improved birefringence in a broad range of wavelength bands. The fundamental mode of birefringence and dispersion for such a PCF is analyzed numerically using the finite element method (FEM) with perfectly matched layer. Our proposed designed PCF contains a finite number of circular and elliptical air holes that are linearly placed to a straight line in a circle of boundary. It is demonstrated that our hybrid PCF can be used for different sensors and telecommunication applications cause it offers 0.0004 to 0.0009 birefringence and low dispersion (-4 to 8) ps/(km·nm) and nonlinear coefficient 7.8 to 3.7 W^-1km^-1 for a wide wavelength range 1.15 to 1.65 μm. Moreover our proposed design gives confinement loss 10^-7.5 to 10^-5.7 (dB/km) and effective area 1.45 × 10^-11 to 2.1×10^-11 μm² within this wide wavelength range.

Design of a photonic crystal fiber for dispersion compensation over telecommunication bands

This paper presents a microstructure optical fiber based on an hexagonal structure for dispersion compensation in a wideband transmission system. According to simulation, negative dispersion coefficient of - 562 ps/(nm.km) and relative dispersion slope (RDS) close to that of single mode fiber (SMF) of about 0.0036 nm-1 is obtained at 1550 nm wavelength. Besides the proposed hexagonal microstructure optical fiber (H-MOF) offers high birefringence of 3.06×10-2. Due to having better optical properties, this proposed fiber can be effectively used in broadband dispersion compensation and sensing applications.

A slope matched microstructure optical fiber for dispersion compensation over S + C+ L wavelength bands

This paper presents a microstructure optical fiber based on an octagonal structure for dispersion compensation in a wide range of wavelengths. It is shown theoretically that it is possible to obtain negative dispersion coefficient of - 821 ps/(nm.km) and relative dispersion slope (RDS) close to that of single mode fiber (SMF) of about 0.0036 nm-1 at 1550 nm wavelength. Besides the proposed octagonal microstructure optical fiber (O-MOF) offers high birefringence of 1.86×10-2. Due to having superior optical properties, this proposed fiber with modest number of design parameters can be effectively used in broadband dispersion compensation and sensing applications.