Photonic crystal fiber with high nonlinearity and extremely negative dispersion

Abstract

In this manuscript, we have designed a circular photonic crystal fiber (PCF) having three rectangular holes filled with GaP in the core region, three air hole rings and one annular air ring in the cladding region. We found highest negative dispersion for the 1.8 μm pitch along with very low confinement loss at wavelength 1.55 μm. This designed PCF offers high nonlinearity (39,612 W −1 km −1 ) and high negative dispersion (− 6586 ps nm −1 km −1 ) along with zero confinement loss at 1.55 μm wavelength. We also compared the proposed PCF with the previously published PCF structure and found that the nonlinearity and negative dispersion of the designed PCF are very high in comparison to circular air hole based PCF. Other performance parameters viz. birefringence, numerical aperture, effective area, and effective material loss are also analyzed.

Negative frequencies in pulse propagation equations and the double analytic signal

“…This substitution results in a total of 20 nonlinear terms. We need to determine which ones to include in the term p NL,ω , that we obtain the UPPE of the AS (20) by applying the folding operation (26)-equation (28). For example, the spm p term |e p | 2 e p in the DAS equation:…”

“…It has taken many years to uncover these nonlinear terms because the conditions where negative frequencies are relevant have only recently become experimentally accessible. Technological advances in the form of ultra short pulses (on the order of a few optical cycles at ∼10 fs) [26] and the fabrication of highly-nonlinear fibers (as photonic-crystal fibers with a nonlinear coefficient γ ∼ 10 4 W −1 km −1 ) [27,28] have led to a new regime of extreme nonlinear optics (XNLO) [21], where negative frequencies are crucial. The reason is that the negative frequency branch of the dispersion relation is far from the positive branch.…”

Circular lattice benzene-core PCFs with flat near-zero dispersion for low-power broad-spectrum supercontinuum generation

“…Lanh et al [27] showed that PCFs containing C 6 H 5 NO 2 cores in circular matrices have lower attenuation and higher nonlinearity compared to square and hexagonal lattices, which have potential applications in SC spectrum generation. A number of research papers on the use of circular PCFs have been published in recent years [32,[34][35][36]. Pandey et al [35] initially proposed a circular PCF with three rectangular holes in the core region filled with GaP and found that the negative dispersion and nonlinearity of this PCF are very high.…”

“…A number of research papers on the use of circular PCFs have been published in recent years [32,[34][35][36]. Pandey et al [35] initially proposed a circular PCF with three rectangular holes in the core region filled with GaP and found that the negative dispersion and nonlinearity of this PCF are very high. They further extended the four rings of air holes toward the cladding area interwoven by four tiny air hole rings to acquire low dispersion and confinement loss [36].…”