M. Selim Habib

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.

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.

Highly birefringent modified circular photonic crystal fiber for dispersion management over E+S+C+L wavelength bands

In this paper, we propose a highly birefringent modified circular photonic crystal fiber (M-CPCF). The proposed structure is found extremely suitable for chromatic dispersion compensation of standard single mode fiber (SMF) over E+S+C+L wavelength bands. Finite element method (FEM) with perfectly matched layer boundary condition has been applied to explore its guiding properties. Simulation results confirm the possibility of large negative dispersion coefficient and relative dispersion slope (RDS) of -650 ps/(nm·km) and 0.0036 nm-1 respectively at 1550 nm wavelength and effective dispersion coefficient of about ± 0.5 ps/(nm·km) from 1360 to 1640 nm wavelength. The proposed fiber also demonstrates a high birefringence of order 2.1×10-2 that allows the fiber to maintain a single polarization. The proposed fiber can be a promising candidate in high speed transmission system for broadband dispersion compensation and sensing applications as well.

Modelling of dispersion flattened photonic crystal fibers for communication application

We present a photonic crystal fiber (PCF) for shaping nearly zero ultra-flattened dispersion and low splice loss at telecom window. The finite-element method with perfectly matched layers boundary condition is used to investigate the guiding properties. Simulation results reveal that, ultra-flattened dispersion of 0 ± 0.8 ps/nm/km is obtained in a wavelength range of 1.33 to 1.71 μm with low splice loss of 3.82 dB in the entire band of interest from an eight-ring PCF.