Supercontinuum Generation Research Papers - Academia.edu (original) (raw)

We solve a system of generalized nonlinear Schr¨odinger equations to study the nonlinear dynamics of ultrashort pulse propagation in multimode fibers. Due to pulse walk-off, permanent intermodal power transfer between modes is observed even in absence of phase matching. The strength of intermodal effects is found to depend strongly on modal symmetries, which results in preferential coupling between the LP0n modes. The scaling of nonlinear multimode effects in large-core fibers for the generation of ultra-high power spectral density supercontinua is finally discussed.

This paper presents the design of a photonic crystal fiber, which promises to yield very large optical nonlinearity ~151 W^(-1) km^(-1) at 1.55 μm wavelength. The fiber possess two zero dispersion points whose location can be tuned by varying air hole diameter and hole pitch. The fiber dispersion is anomalous between these two zero dispersion points and its value is moderate. The fiber has been used to numerically simulate optical supercontinuum (SC) generation using low power pump pulses of 50 fs duration at 1.55 μm wavelength. At the end of 15 cm fiber SC broadening of about 1200 nm and 1700 nm can be achieved with pulses of 1 kW and 5 kW peak power respectively.

- by Mohit Sharma
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- Optics, Nonlinear optical waves, optical spatial solitons, Dispersion, Solitons
- by kinkiat90 chang
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- Optics, Supercontinuum Generation, Raman amplification
- by iaeme iaeme
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- Physics, Supercontinuum Generation, Optical fiber, Soliton
- by Kay Schuster
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- Materials Engineering, Glass, Silica, Supercontinuum Generation

We show numerically that both the modified Korteweg–de Vries and the sine-Gordon models are conducive to the generation of supercontinua with spectral bandwidths of several octaves, when an intense short pulse is launched as the initial condition. These models beyond the slowly-varying-envelope approximation could play an important role in modeling supercontinuum generation in gas-filled hollow waveguides.

- by Dumitru Mihalache and +2
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- Supercontinuum Generation, Few-Cycle Solitons
- by Abdur Razzak
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- Nonlinear Fiber Optics, Nonlinear Optics, Numerical Simulation, Optical

A photonic crystal fibre with hollow core filled with toluene is considered as a new system for coherent supercontinuum generation. The dispersion characteristics are studied for various geometrical parameters of photonic crystal fibres. Two structures with lattice constant 2 μm, filling factors d/Λ 0.3 and 0.35 and toluene core of diameters of 3.34 and 3.23 μm have flat dispersion in the near infrared range. The structure with d/Λ=0.3 has all-normal dispersion characteristics in whole near-infrared wavelength range, while the second structure (d/Λ=0.35) has anomalous dispersion for wavelengths longer than 1.5 μm. Although confinement losses in the considered structures are as high as 0.4 dB cm −1 , we show that the generation of coherent supercontinuum in the range 1.0-1.7 μm with the pulse energy conversion of 16% is feasible in 4 cm long fibre samples with standard fibre femtosecond lasers.

- by Lanh Chu Van
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- Optofluidics, Supercontinuum Generation, Photonic Crystal Fibre (PCF)
- by Harri Kaartinen
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- LiDAR, Region growing, Data Fusion, Supercontinuum Generation
- by Mathivanan Damodaran
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- Fiber Lasers, Supercontinuum Generation, Edfa

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.

- by Lanh Chu Van
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- Supercontinuum Generation, Photonic Crystal Fibers

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.

- by Lanh Chu Van
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- Supercontinuum Generation, Photonic Crystal Fibers

We demonstrate a robust, all-solid-state approach for the generation of microjoule subcycle pulses in the midinfrared through a cascade of carefully optimized parametric-amplification, difference-frequency-generation, spectral-broadening, and chirp-compensation stages. This method of subcycle waveform generation becomes possible due to an unusual, ionization-assisted solid-state pulse self-compression dynamics, where highly efficient spectral broadening is enabled by ultrabroadband four-wave parametric amplification phase matched near the zero-group-velocity wavelength of the material.

- by Aleksandr Lanin and +1
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- Supercontinuum Generation, Mid-Infrared, Ultrashort Pulse

Microstructured optical fibers (MOF) can be seen as next generation fiber of significance in advancing the compact optics because of its excellent compatibility in integrated optics. However, the degradation of their physicochemical properties limits their efficiency and lifetime. Atmospheric moisture is responsible for the degradation of amorphous systems especially chalcogenide glasses. In the light of previously reported studies, in order to clarify the aging process continuously evolving in sulfide microstructured optical fiber over time, a detailed investigation of this phenomenon has been conducted. The time dependent transmission and glass chemical deterioration have been studied for As2S3 MOF with regard to their exposure to different atmospheric conditions. Results show a substantial impact of atmospheric moisture through an interaction with the glass network. Significant improvement has been registered by storing the fibers under dry atmosphere.

- by Oussama Mouawad and +1
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- Materials Science, Mechanical Behavior Of Materials, Materials Science and Engineering, Materials development

An As2S3 fiber-based supercontinuum source that covers 3500 nm, extending from near visible to the midinfrared, is successfully reported by using a 200-fs-pulsed pump with nJ-level energy at 2.5 μm. The main features of our fiberbased source are two-fold. On the one hand, a low-loss As2S3 microstructured optical fiber has been fabricated, with typical attenuation below 2 dB∕m in the 1–4 μm wavelength range. On the other hand, a 20-mm-long microstructured
fiber sample is sufficient to enable a spectral broadening, spreading from 0.6 to 4.1 μm in a 40 dB dynamic range.

- by Oussama Mouawad and +1
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- Materials Science, Infrared Astronomy, Materials Chemistry, Infrared Optics

This article presents a three-layer index guided lead silicate (SF57) photonic crystal fiber which simultaneously promises to
yield large effective optical nonlinear coefficient and low anomalous dispersion that makes it suitable for supercontinuum
(SC) generation. At an operating wavelength 1550 nm, the typical optimized value of anomalous dispersion and effective
nonlinear coefficient turns out to be ~4 ps/km/nm and ~1078 W−1km−1, respectively. Through numerical simulation, it is
realized that the designed fiber promises to exhibit three octave spanning SC from 900 to 7200 nm using 50 fs ‘sech’
optical pulses of 5 kW peak power. Due to the cross-phase modulation and four-wave mixing processes, a long range of
red-shifted dispersive wave generated, which assists to achieve such large broadening. In addition, we have investigated
the compatibility of SC generation with input pulse peak power increment and briefly discussed the impact of nonlinear
processes on SC generation.

- by Mohit Sharma
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- Optical Fiber Communications, Fiber Optics, Nonlinear Optics, Photonic Crystals

The efficiency and the stability of As2S3 microstructured optical
fibres (MOFs) are limited by the shift of their optical properties that occurs over time due to a naturally induced aging process. Such sensitivity becomes more crucial for long optical path. Among the variety of fibre designs, the MOFs are developed for promising photonics applications such as supercontinuum generation for example. In the present work, we carried out an extensive aging study on As2S3 chalcogenide MOFs in ambient
atmosphere. The evolution of the fibre transmission spectrum has been studied with regards to exposure time. The analysis of the transmission line profile was performed in terms of different spectral components Gaussian in shape and the infrared absorption bands have been attributed to the
corresponding chemical groups' vibration modes or overtones. The timedependent evolution of fibre attenuation has been studied as well as its longitudinal evolution for a given exposure time. Previous knowledge of extinction coefficient inherent to vibration components allows to predict their corresponding concentration. The content of hydroxyl groups tightly bonded to the glass network of the sulphide MOF core decreases exponentially with distance away from the MOF extremity. The report results show that a deleterious aging effect occurs over the first hours and days of exposure. This have crucial implications for storage and employment techniques and requires holes airproofing technique.

- by Oussama Mouawad and +1
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- Materials Engineering, Materials Science, Materials Chemistry, Materials Characterisation
- by Jing Zhang
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- Mechanical Engineering, Water, Energy Conversion, Supercontinuum Generation
- by Xinben Zhang
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- Optics, Nonlinear Optics, Supercontinuum Generation, Photonic crystal fiber

In this work, we report the experimental observation of supercontinua generation in two kinds of suspended-core microstructured soft-glass optical fibers. Low loss, highly nonlinear, tellurite and As2S3 chalcogenide fibers have been fabricated and pumped close to their zerodispersion wavelength in the femtosecond regime by means of an optical parametric oscillator pumped by a Ti:Sapphire laser. When coupled into the fibers, the femtosecond pulses result in 2000-nm bandwidth supercontinua reaching the Mid-Infrared region and extending from 750 nm to 2.8 μm in tellurite fibers and 1 μm to 3.2 μm in chalcogenide fibers, respectively

A novel procedure to produce transform-limited optical pulses with high peak power using supercontinuum generation in an optical fiber has been developed. These pulses have been created using a mode-locked Ti:Sapphire oscillator to generate 18 fs pulses at 795.3 nm with energy of 4 nJ and bandwidth of 46 nm. A high power chirped pulse amplification was used to produce femtosecond pulses of 2.6 W at 32 fs for wavelength 800 nm. To achieve extreme pulse compression in the few-cycle regime, the 32 fs pulses have been injected through a hollow-fiber filled with neon gas to generate supercontinuum pulses then temporally compressor by multilayer-chirped mirrors. This arrangement enabled the generation of a five-octave-wide supercontinuum ultrafast pulses over a wide frequency range from 500 THz to 333 THz. That broad bandwidth has allowed to produce transform limited pulses of 6.01 fs time duration and 120 GW peak power that exceeds the previously observed value of 80 GW for similar pulses. The observed results may give an opportunity to generate ultrashort pulses with extreme short optical wavelength using high harmonic generation that are needed for ultrafast spectroscopy in femtochemistry.

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.

We present a new hyperspectral darkfield imaging system with a scanned broadband supercontinuum light source. We observed the specific attachment of the functionalized gold plasmonic nanoparticles (AuNPs) targeting CD44(+) human breast cancer cells by conventional and by proposed hyperspectral darkfield microscopy. This wide-field and low phototoxic hyperspectral imaging system has been successful for performing spectral three-dimensional (3D) localization and spectroscopic identification of CD44-targeted PEGylated AuNPs in fixed cell preparations. Such spatial and spectral information is essential for the improvement of nanoplasmonic-based imaging, disease detection and treatment in complex biological environment. Presented system capability for 3D NP tracking will also enable investigation of specific sub-cellular activity with the use of NPs as spectral sensors.

- by Eric Bergeron
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- Microscopy, Biophotonics, Metal Nanoparticles, Humans
- by Marcin Ziołek
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- Fused Silica Etching, Supercontinuum Generation, Optical physics, Femtosecond

We solve a system of generalized nonlinear Schr¨ odinger equations to study the nonlinear dynamics of ultrashort pulse propagation in multimode fibers. Due to pulse walk-off, permanent intermodal power transfer between modes is observed even in absence of phase matching. The strength of intermodal effects is found to depend strongly on modal symmetries, which results in preferential coupling between the LP_0n modes. The scaling of nonlinear multimode effects in large-core fibers for the generation of ultra-high power ...

We analyze optical and structural aging in As2S3 microstructured optical fibers (MOFs) that may have an impact on mid-infrared supercontinuum generation. A strong alteration of optical transparency at the fundamental OH absorption peak is measured for high-purity As2S3 MOF stored in atmospheric conditions. The surface evolution and inherent
deviation of corresponding chemical composition confirm that the optical
and chemical properties of MOFs degrade upon exposure to ambient
conditions because of counteractive surface process. This phenomenon
substantially reduces the optical quality of the MOFs and therefore restrains
the spectral expansion of generated supercontinuum. This aging process is well confirmed by the good matching between previous experimental results and the reported numerical simulations based on the generalized nonlinear Schrödinger equation.

- by Suman Bagchi
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- Nonlinear Optics, Condensed Matter, Proceedings, Plasma
- by Pedro Corredera
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- Optics, Medical Imaging, Fiber Optics, Telecommunications

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.

- by Lanh Chu Van
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- Supercontinuum Generation, Photonic Crystal Fibers
- by Eric Monberg
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- Optics, Quantum Physics, Nonlinear Optics, Supercontinuum Generation

In this work we have studied the fragmentation of gold nanoparticles (NPs) after generation by femtosecond laser ablation of a solid target in deionized water. The fragmentation process was carried out using two different types of radiation: direct ultra-fast pulses and super-continuum radiation focused in the colloidal solution. In the former case, IR pulses were applied both in low and high fluences regime, while in the latter, super-continuum was generated by an external sapphire crystal. In this last case, to assess the effects of the different spectral bands present in the super-continuum for fragmentation, we have determined different efficiency regions. From the analysis of optical extinction spectra and Transmission Electron Microscopy (TEM) histograms we can conclude that the main mechanism is linear absorption in the visible region. Likewise, the super-continuum generated in water during fragmentation resulted more efficient than that obtained externally by the sapphire crystal. This fact can be attributed to the broadening of the water continuum band originated due to large intensity used for generation. TEM and Small Angle X-ray Scattering (SAXS) measurements support the results found from optical extinction spectroscopy.

- by Gustavo A Torchia
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- Radiation, Water, Small angle X-ray and neutron scattering, Spectroscopy
- by Mourad Zghal
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- Nonlinear Optics, Supercontinuum Generation, Experimental Study, Optical physics
- by Arnan Mitchell
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- Optics, Nonlinear Optics, Light, Supercontinuum Generation

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 (n 2 = 4.3×10 −19 m 2 /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 10 2 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.

- by Lanh Chu Van
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- Supercontinuum Generation, Photonic Crystal Fibre (PCF)
- by Boon Ooi
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- Nanophotonics, Self Assembly, Photoluminescence, Quantum Dots
- by H. Ludvigsen
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- Quantum Physics, Nonlinear Optics, Fiber optic sensor, Supercontinuum Generation
- by Gustavo A Torchia
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- Radiation, Water, Small angle X-ray and neutron scattering, Spectroscopy
- by E. Tsoy
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- Physics, Mathematical Sciences, Solitons, Physical sciences