Generation of stable temporal doublet by a single-mode silicon core optical fiber

Abstract

A highly nonlinear single-mode anomalous dispersion silicon-core fiber (SMADSF) is designed and optimized at the operating wavelength of 2.2 µm for the purpose of generating stable temporal pulse doublets. To designate the output pulse pair as a perfect Gaussian doublet, two new parameters, dissimilarity factor (ρ_g) and co-similarity index (μ_cs) are introduced. Different input pulse parameters such as power, pulse width and chirp are optimized to obtain Gaussian temporal doublets at the shortest optimum length (~ few cm) which is sufficiently smaller in comparison to silica fibers reported earlier. The output pulse pairs remain as a doublet for quite a good stability length. In view of serving practical purposes, the possibilities of fluctuations of input power and pulse width are included to investigate the changes in stability length and effective repetition rate (ERR). The change in ERR along the fiber length produces a remarkable change in free carrier concentration in core, which has also been taken into account for the first time as per our knowledge to obtain the temporal pulse doublet in the so designed Si-core fiber.

Investigation of Silicon Core-Based Fiber Bragg Grating for Simultaneous Detection of Temperature and Refractive Index

“…However, there were no obviously different results between 12 µm and other larger cladding diameter sizes (e.g., 125 µm diameter), especially for reflectance. According to past research [12], the main condition for single-mode operation of SCF is that the core diameter of SCF should be smaller than 1 µm. To investigate this condition, we simulated transmission transparency with a different radius of silicon core, from 0.45 to 0.75, and transmission mode, respectively, without fiber Bragg grating design.…”

“…Most of the recent research into silicon core-based fibers shows nonlinear effects because they have a higher nonlinear coefficient than fused silica, e.g., four-wave mixing and supercontinuum generation [10,11]. Compared to fused silica fibers, the core diameter of SCFs needed to be reduced to smaller than 1 µm for single-mode operation [12]; in other words, SCFs has more potential applications for nonlinear effect. Apart from nonlinear effects, U. J. Gibson used a 30 W CO 2 laser to fabricate silicon core fiber Bragg grating in 2017 [13].…”

Semiconductor Core Optical Fibers for the Purpose of Nonlinear pulse Reshaping

“…Two dimensionless parameters r and μ are considered here, where the first one signifies the relative importance of two photon absorption (TPA) and presented as ( ), being the TPA co-efficient. The second dimensionless parameter μ defines the impact of free carrier dispersion (FCD) [16,18]. For relatively low repetition rate of the input pulse, the TPA-induced free carrier density N c can be calculated from the rate equation [16]  …”