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In this paper, we demonstrated the ability of a hexagonal photonic crystal fiber (PCF) with a hollow core infiltrated with nitrobenzene (C6H5NO2) to generate a broad SC spectrum at low peak powers. Due to the non-uniformity of the air hole diameters, our new design allows for simultaneous optimization of features, resulting in near-flat, near-zero dispersion, a small effective mode area, and low attenuation for efficient spectral broadening. We selected two optimal structures from the simulation results to analyze the nonlinear properties and supercontinuum generation. The first fiber, #HF1, with a lattice constant of 1.0[Formula: see text][Formula: see text]m and a filling factor of 0.45, operates in all-normal dispersion and produces spectral SC ranging from 0.81[Formula: see text][Formula: see text]m to 1.919[Formula: see text][Formula: see text]m with a pump wavelength of 1.56[Formula: see text][Formula: see text]m, a pulse duration of 90[Formula: see text]fs, and peak power of 0.133[Formula: see text]kW propagated in a 1 cm fiber length. The #HF2 fiber (lattice constant of 2.0[Formula: see text][Formula: see text]m, filling factor of 0.3) has an extended SC spectrum from 0.792[Formula: see text][Formula: see text]m to 3.994[Formula: see text][Formula: see text]m, a pump wavelength of 1.55[Formula: see text][Formula: see text]m, a pulse width of 110[Formula: see text]fs, a peak power of 0.273[Formula: see text]kW propagated in a 15[Formula: see text]cm fiber length. The proposed fiber may be a new-generation optical fiber suitable for low-peak power all-fiber optical systems to replace glass-core glass fiber.

In this work, a flat-top and broadband supercontinuum (SC) generation in photonic crystal fibers (PCFs) infiltrated with carbon tetrachloride (CCl[Formula: see text] with different air hole diameters in the cladding has been introduced. The optical properties of the fundamental mode are analyzed by numerical simulation. Based on the obtained results, two optimized PCFs with small dispersion are proposed and verified against SC generation in detail. The first fiber has an all-normal dispersion of [Formula: see text]9.376[Formula: see text]ps.nm[Formula: see text].km[Formula: see text] at the pump wavelength of 0.98[Formula: see text][Formula: see text]m, generating broadband of 768[Formula: see text]nm and flat-top with only 0.3[Formula: see text]nJ of input energy and time duration of 90[Formula: see text]fs. In the meantime the dispersion property of the second fiber is anomalous, which equals 1.105[Formula: see text]ps[Formula: see text][Formula: see text][Formula: see text]nm[Formula: see text][Formula: see text][Formula: see text][Formula: see text]km[Formula: see text] at 1.3[Formula: see text][Formula: see text]m pump wavelength. The second fiber generates a SC spectrum of 1,751.1[Formula: see text]nm with input energy and time duration of 0.55[Formula: see text]nJ and 55[Formula: see text]fs, respectively. Proposed fibers are suitable for all-fiber SC sources which could lead to new low-cost all-fiber optical systems.

In this paper, we propose the solid-core photonic crystal fibers (PCFs) with hexagonal cladding infiltrated with propanol in the air-holes. The dispersion characteristics and zero- dispersion wavelengths of these PCFs have been compared with previous publications and analyzed in detail. By investigating the dependence of the dispersion characteristics on the air-hole diameters, we determine the optimal structures with 1 µm of that. The PCF infiltrated with propanol exhibits flatter and smaller dispersion characteristic and the zero-dispersion wavelength shifted towards a longer wavelength, 24 nm compared with ethanol permeable PCFs [17]. This result shows that structure with a diameter of air-holes by 1µm is suitable for supercontinuum (SC) generation in the near- infrared wavelength range.

In this study, we demonstrate the ability to generate a broad supercontinuum (SC) spectrum with a low peak power of square (S-PCF) and circular (C-PCF) lattice photonic crystal fibers with hollow-core infiltrated with carbon tetrachloride (CCl4). The dispersion and nonlinear characteristics have been numerically analyzed in detail and compared to select the optimal structures for SC generation and evaluate the SC generation efficiency for each PCF. With four optimal proposed structures, the all-normal dispersion of square PCF (#SF1) is found to be flatter and smaller. This results in its SC bandwidth reaching 901 nm at 1.095 μm pumping wavelength which is broader than that of circular PCF (#CF1) (768 nm at 0.98 μm wavelength) despite the lower nonlinear coefficient and higher confinement loss. For the anomalous dispersion regime, #CF2 fiber provides a wider SC spectrum (1753.1 nm) with a peak power of 10 kW compared to #SF2 (1689.6 nm) with a peak power of 13.75 kW thanks to the higher nonlinear coefficient and smaller confinement loss. With the higher nonlinearity of CCl4, the proposed fibers can be a new generation of optical fibers, suitable for low peak power all-fiber optical systems replacing glass core fibers.

We report a numerical study on mid-infrared (IR) supercontinuum (SC) generation in the regime of all normal dispersion using lead bismuth gallate glass photonic crystal fiber. This fiber allows the changing of dispersion from anomalous dispersion to ultra-flat normal dispersion in the wavelength range of over 930 nm by filling its cladding holes with C2Cl4. Using a 12.5 kW laser pulse at 2.8 µm as a pump source, we demonstrate that a broad and highly coherent SC generation spectrum is generated in the wavelength range of 1.2 μ m –3.4 μ m with the effects of vacuum noise. However, pulse-to-pulse relative intensity noise significantly decreases the coherence. These interesting optical properties make the proposed C2Cl4—infiltrated fiber highly promising for various applications in the mid-IR regime, particularly, spectroscopy, optical coherence tomography, and metrology.

Kerr nonlinear coupler consists of two nonlinear oscillations in which one of them linearly excited by an external classical field. This is assumed to be decomposed into two parts: a coherent part and a randomly fluctuating chaotic component that is a δ-correlated, Gaussian, Markov, stationary process (white noise). We solve a set of coupled stochastic integro-differential equations involved in the problem with all initial conditions and obtain analytical formulae for the complex probability amplitudes of finite n-photon Fock states. Especially, our study shows that the system is also able to generate maximally entangled states and, as a consequence, the coupler discussed behaves as a two-qubit system and the results compared with those derived previously in the literature.

In this paper, a photonic crystal fiber (PCF) with core infiltrated with Nitrobenzene is proposed and investigated. Its feature properties as the effective refractive index, effective mode area, chromatic dispersion, and confinement loss have been numerically simulated. The obtained results show that characteristic quantities of PCF with core infiltrated with Nitrobenzene (PCF-N) having some advantages in comparison to PCF with core infiltrated with Toluene (PCF-T) at 1.55μm wavelength. For the purpose of supercontinuum generation, two optimal structures with lattice constants 2.0μm and 2.5μm with filling factors d/Ʌ = 0.3 are identified.

We investigate the electronic, photocatalytic and optical properties of a fully hydrogenated indium nitride H–InN–H monolayer under biaxial strain e b and external electric field E using density functional theory. Our findings demonstrate that the H–InN–H monolayer is a semiconductor with an indirect energy gap of 2.591 eV. Under a biaxial strain or electric field, the indirect-direct band gap transition can occur and its band gap depends dramatically on the e b and E. Our analysis of band edge alignment shows that the H–InN–H monolayer can possess photocatalytic activity for water splitting when an electric field or biaxial strain is applied. The optical characteristics of the H–InN–H monolayer depends greatly on the strain. The first optical gap of the H–InN–H monolayer is at the incident energy light of 3.320 eV and the tensile strain causes the first optical gap to shift towards the visible light region.

In this paper, we consider the influence of collisional fluctuations on optical phenomena. The fluctuations are taken into account by a simple shift of the constant detuning, involved in a set of optical Bloch equations by collision frequency noise in which this noise is modelled by a two-step random telegraph signal. Following that, the stochastic Bloch equations can be solved analytically in an exact way. As an example, we consider in detail the Mollow spectrum of resonance fluorescence for the case of an arbitrary detuning of the laser frequency, where velocity of the emitters simply has a deterministic value or is distributed with the Maxwell–Boltzmann density in which volume of the buffer gas is arbitrary.

In this paper we present a numerical study on the optimization of dispersion of a photonic crystal fiber infiltrated with water-ethanol mixtures. The advantage of such an approach stems from the fact that the dependence of the refractive index on temperature is larger in liquids than in solid materials. Here, we examine photonic crystal fibers with a regular, hexagonal lattice and with various geometrical and material parameters, such as different number of rings of holes, various lattice constants and the size of core and air-holes. Additionally, for the optimized structure with flat dispersion characteristics, we analyze the influence of temperature and concentration of the ethanol solution on the dispersion characteristic and the zero dispersion wavelength shift of the fundamental mode.

We present a numerical study of the dispersion characteristic modification in a nonlinear photonic crystal fibre (PCF) infiltrated with organic solvents. The PCF is made of PBG08 glass and was developed in the stack-and-draw process. The PBG08 glass has a high refractive index (n < 2.0), high nonlinear refractive index (n2 = 4.3×10−19 m2/W) and good rheological properties that allow for thermal processing of the glass without crystallization. In the numerical study 18 different solvents were used. The dispersion, mode area, and losses characteristics were calculated. The zero dispersion wavelength (ZDW) of the fibre can be shifted towards longer wavelengths by approx. 150 nm by using Nitrobenzene as infiltrating liquid and by a smaller value using other liquids. At the same time the mode area of the fundamental mode increases by approx. 5 to 15% depending on the wavelength considered. The confinement losses increase significantly for six analysed liquids by a few orders of magnitude up to 102 dB/m. Our approach allows to combine high nonlinearities of the soft glass with the possibility to tune zero dispersion wavelength to the desired value.

In this paper we present a study on the dispersion characteristics in the suspended-core optical fibers made of borosilicate of NC21A glass infiltrated with water. Replacement of air with water results in dramatic improvement of the dispersion characteristics in the fibers, valuable in the process of supercontinuum generation. A near-zero flat dispersion can be achieved in the anomalous or normal dispersion range for various diameters of the core.

We present a numerical study of the dispersion characteristic modification of nonlinear photonic crystal fibers infiltrated with liquids. A photonic crystal fiber based on the soft glass PBG-08, infiltrated with 17 different organic solvents, is proposed. The glass has a light transmission window in the visible-mid-IR range of 0.4-5 μm and has a higher refractive index than fused silica, which provides high contrast between the fiber structure and the liquids. A fiber with air holes is designed and then developed in the stack-and-draw process. Analyzing SEM images of the real fiber, we calculate numerically the refractive index, effective mode area, and dispersion of the fundamental mode for the case when the air holes are filled with liquids. The influence of the liquids on the fiber properties is discussed. Numerical simulations of supercontinuum generation for the fiber with air holes only and infiltrated with toluene are presented.

Temperature change of the water infiltrated PCF is an interesting and practical method for a dynamical fine tuning of dispersion in active dispersion shift compensating systems. In this paper we present a numerical study on the influence of the temperature of infiltrated water on the dispersion and modal characteristics of photonic crystal fiber. We study regular hexagonal lattice photonic crystal fibers with various geometrical parameters using finite element method.