Showing papers on "Supercontinuum published in 2023"
TL;DR: In this article , a dual-state vector soliton (DSVS) is reported in a mode-locked fiber laser under appropriate birefringence, and two vector states emitted alternatively display double-peak and Lorentz-shaped spectral profile, respectively.
Abstract: Vector soliton originates from the soliton trapping dynamics via cross-phase modulation (XPM) which has been used to achieve supercontinuum, optical switching and optical analog of gravity-like potentials. Dual-state vector soliton (DSVS) is reported in mode-locked fiber laser under appropriate birefringence. Two vector soliton states emitted alternatively display double-peak and Lorentz-shaped spectral profile, respectively. The two orthogonally polarized components of the double-peak spectrum exhibit obvious redshift and blueshift, respectively, while the frequency shift for the other state is limited even with the reversed shift direction, which illustrates a unique vector soliton evolution dynamic. DSVS originates from the pulse trapping induced by XPM, as well as the periodical evolution and frequency shift induced by self-phase modulation under dispersion-managed condition. The vector period-doubling phenomenon will further enrich the understanding about soliton, and also guide the design of mode-locked laser.
6 citations
TL;DR: In this paper , an enhanced supercontinuum generation (SCG) was demonstrated in integrated silicon nitride (Si3N4) waveguides incorporating highly nonlinear graphene oxide (GO) in the form of 2D films.
Abstract: Enhanced supercontinuum generation (SCG) is experimentally demonstrated in integrated silicon nitride (Si3N4) waveguides incorporating highly nonlinear graphene oxide (GO) in the form of 2D films. On‐chip integration of the 2D GO films with precise control of their thickness is realized by using a transfer‐free and layer‐by‐layer coating method. The control of the film length and coating position is achieved via window opening in the upper silica cladding of the photonic integrated chips. Detailed SCG measurements are performed using the fabricated devices with different waveguide geometries and GO film thicknesses, and the results are compared with devices without GO. Significantly improved spectral broadening of ultrashort optical pulses with ultrahigh peak powers exceeding 1000 W is observed for the hybrid devices, achieving up to 2.4 times improvement in the spectral bandwidth relative to devices without GO. Theoretical analyses for the influence of GO film thickness, coating length, coating position, and waveguide geometry are also provided by fitting the experimental results with theory, showing that there is still significant room for further improvement. This work opens up a new avenue toward improving the SCG performance of photonic integrated devices by incorporating functional 2D materials.
4 citations
TL;DR: In this paper , the authors proposed a method of supercontinuum light generation enhanced by multimode excitation in a precisely dispersion-engineered deuterated SiN (SiN:D) waveguide.
Abstract: We propose a method of supercontinuum light generation enhanced by multimode excitation in a precisely dispersion-engineered deuterated SiN (SiN:D) waveguide. Although a regularly designed SiN-based nonlinear optical waveguide exhibits anomalous dispersion with the fundamental and first-order multimode operation, the center-symmetric light pumping at the input edge has so far inhibited the full potential of the nonlinearity of SiN-based materials. On the basis of numerical analysis and simulation for the SiN:D waveguide, we intentionally applied spatial position offsets to excite the fundamental and higher-order modes to realize bandwidth broadening with flatness. Using this method, we achieved an SNR improvement of up to 18 dB at a wavelength of 0.6 µm with an offset of about 1 µm in the Y-axis direction and found that the contribution was related to the presence of dispersive waves due to the excitation of TE10, and TE01 modes.
3 citations
TL;DR: In this paper , the authors report the experimental generation of a broadband and flat mid-infrared supercontinuum in a silicon-germanium-on-silicon two-stage waveguide.
Abstract: We report the experimental generation of a broadband and flat mid-infrared supercontinuum in a silicon-germanium-on-silicon two-stage waveguide. Our particular design combines a short and narrow waveguide section for efficient supercontinuum generation, and an inverse tapered section that promotes the generation of two spectrally shifted dispersive waves along the propagation direction, leading to an overall broader and flatter supercontinuum. The experimentally generated supercontinuum extended from 2.4 to 5.5 µm, only limited by the long wavelength detection limit of our spectrum analyzer. Numerical simulations predict that the supercontinuum actually extends to 7.8 µm. We exploit the enhanced flatness of our supercontinuum for a proof-of-principle demonstration of free-space multi-species gas spectroscopy of water vapor and carbon dioxide.
3 citations
TL;DR: A comprehensive overview of supercontinuum generation in chip-based platforms, from underlying physics mechanisms up to the most recent and significant demonstrations is presented in this article , where the diversity of integrated material platforms, as well as specific features of waveguides, is discussed.
Abstract: Abstract Frequency conversion in nonlinear materials is an extremely useful solution to the generation of new optical frequencies. Often, it is the only viable solution to realize light sources highly relevant for applications in science and industry. In particular, supercontinuum generation in waveguides, defined as the extreme spectral broadening of an input pulsed laser light, is a powerful technique to bridge distant spectral regions based on single-pass geometry, without requiring additional seed lasers or temporal synchronization. Owing to the influence of dispersion on the nonlinear broadening physics, supercontinuum generation had its breakthrough with the advent of photonic crystal fibers, which permitted an advanced control of light confinement, thereby greatly improving our understanding of the underlying phenomena responsible for supercontinuum generation. More recently, maturing in fabrication of photonic integrated waveguides has resulted in access to supercontinuum generation platforms benefiting from precise lithographic control of dispersion, high yield, compact footprint, and improved power consumption. This Review aims to present a comprehensive overview of supercontinuum generation in chip-based platforms, from underlying physics mechanisms up to the most recent and significant demonstrations. The diversity of integrated material platforms, as well as specific features of waveguides, is opening new opportunities, as will be discussed here.
2 citations
2 citations
TL;DR: In this article , the spectral bandwidth, flatness, and coherence of supercontinuum generation in highly birefringent fiber infiltrated with carbon disulfide is numerically studied with a linearly polarized femtosecond laser (1560 nm wavelength, 90 fs pulse duration).
2 citations
TL;DR: In this paper , the design features of the proposed highly nonlinear circular-lattice-silicon-core and silica-doped-withfluorine (1%) cladding-composite photonic crystal fiber (PCF) in the mid-infrared region of the spectrum were revealed.
Abstract: This paper reveals special design features of the proposed highly nonlinear circular-lattice-silicon-core and silica-doped-with-fluorine (1%) cladding-composite photonic crystal fiber (PCF) in the Mid-infrared region of the spectrum. A region of small negative group velocity dispersion (GVD), managed higher order dispersions (HODs), and unique nonlinearity of silicon have been used to demonstrate a supercontinuum broadening from 1500 nm to 4700 nm with consumption of low input power of 400 W over short fiber distances. It will be also shown that the fiber’s high-level engineered structure finally results in a simple manufacturing process compared with other designed nano-sized silicon PCFs. The designed fiber could have massive potential in gas sensing, soliton effect pulse compression, spectroscopy, material processing, etc.
2 citations
TL;DR: In this article , a post-processing method was proposed to optimize the dispersion shape of chalcogenide fibers for multiscale spanning supercontinuum generation in the mid-infrared range.
2 citations
TL;DR: In this article , a review article deals with various prospects of the Photonic Crystal Fiber (PCF) and its applications in biosensing, refractive index (RI) sensing, biomedical imaging, dispersion compensation, supercontinuum and solitons generation.
Abstract: This review article deals with various prospects of the Photonic Crystal Fiber (PCF) and its applications in biosensing, refractive index (RI) sensing, biomedical imaging, dispersion compensation, supercontinuum and solitons generation. The gradual progress in PCF technology not only explored its application in optical communication but also extended to its effective utilization in PCF-based sensors. PCF is extensively used as a research object in order to curb the positive dispersion by changing either its cladding or core structure. Some existing works also focused on obtaining high nonlinearity in the PCF structures since high nonlinear PCF is used to direct the light in the fiber core only so that light can travel a larger distance without any alteration. But, nowadays, the modern era of optical fiber technology has been more inclined towards PCF-based surface plasmon resonance (SPR) biosensors or RI sensors. The functional mechanism of a biosensor relies on SPR which involves fiber integrated with plasmonic metals (i.e. gold, silver, copper, etc.) as these metals are responsible for the sensitivity of a biosensor. But, the major drawback of plasmonic metals is that they exhibit poor biomolecule adsorption. Therefore, this review mainly explores the possible way such as the incorporation of 2D/TMD materials (i.e. graphene, MoS2, etc.) to increase biomolecule adsorption. These materials play an important role to increase the sensitivity of a biosensor. Hence, metal/2D/TMD based combined heterostructure opens a suitable study window in the field of SPR biosensing that finds its application in cholesterol detection, cancer cell detection, DNA detection, protein and glucose sensing.
2 citations
TL;DR: In this article , the authors present a numerical simulation tool for mixed and cascaded nonlinearities, which uses anti-aliasing strategies to avoid spurious light resulting from a finite simulation bandwidth.
Abstract: Nonlinear optical frequency conversion is of fundamental importance in photonics and underpins countless of its applications: Sum- and difference-frequency generation in media with quadratic nonlinearity permits reaching otherwise inaccessible wavelength regimes, and the dramatic effect of supercontinuum generation through cubic nonlinearities has resulted in the synthesis of broadband multi-octave spanning spectra, much beyond what can be directly achieved with laser gain media. Chip-integrated waveguides permit to leverage both quadratic and cubic effects at the same time, creating unprecedented opportunities for multi-octave spanning spectra across the entire transparency window of a nonlinear material. Designing such waveguides often relies on numeric modeling of the underlying nonlinear processes, which, however, becomes exceedingly challenging when multiple and cascading nonlinear processes are involved. Here, to address this challenge, we report on a novel numeric simulation tool for mixed and cascaded nonlinearities that uses anti-aliasing strategies to avoid spurious light resulting from a finite simulation bandwidth. A dedicated fifth-order interaction picture Runge–Kutta solver with adaptive step-size permits efficient numeric simulation, as required for design parameter studies. The simulation results are shown to quantitatively agree with experimental data, and the simulation tool is available as an open-source Python package ( pychi).
TL;DR: In this article , chromatic dispersion properties of transverse Anderson localization optical fiber (TALOF) and their implications on broad band supercontinuum (SC) generation are discussed.
Abstract: In this paper, we discuss chromatic dispersion properties of transverse Anderson localization optical fiber (TALOF) and their implications on broad band supercontinuum (SC) generation. Our dispersion study reveals a clear correlation between the Anderson localization length and the dispersion properties of highly localized TALOF modes. We demonstrate that the zero dispersion wavelength can be tuned over more than 300 nm within the same fiber by selected excitation of specific modes. We exploit this unique TALOF property, which we validated with rigorous finite-element modeling, to generate multi octave spanning SC ranging from 460–1750 nm, highlighting the great potential of disordered Anderson localization fibers for nonlinear applications.
TL;DR: In this paper , a supercontinuum broadband light source was used to simultaneously monitor atmospheric gaseous compounds and particulate matter, which would further advance our understanding on gas-particle heterogeneous interactions in the context of climate change and air quality.
Abstract: A novel instrument based on broadband cavity-enhanced absorption spectroscopy has been developed using a supercontinuum broadband light source, which showcases its ability in simultaneous measurements of the concentration of NO2 and the extinction of particulate matter. Side-by-side intercomparison was carried out with the reference NOx analyzer for NO2 and OPC-N2 particle counter for particulate matter, which shows a good linear correlation with r2 > 0.90. The measurement limits (1σ) of the developed instrument were experimentally determined to be 230 pptv in 40 s for NO2 and 1.24 Mm-1 for the extinction of particulate matter in 15 s. This work provides a promising method in simultaneously monitoring atmospheric gaseous compounds and particulate matter, which would further advance our understanding on gas-particle heterogeneous interactions in the context of climate change and air quality.
TL;DR: In this paper , the authors studied the spectral characteristics of a broadband noise-like pulse laser by scanning the laser operation over a random sample of 50,000 polarization settings, and quantitatively quantified that these broadest bandwidths are generated in only 0.5% of cases.
Abstract: Abstract The noise-like pulse regime of optical fiber lasers is highly complex, and associated with multiscale emission of random sub-picosecond pulses underneath a much longer envelope. With the addition of highly nonlinear fiber in the cavity, noise-like pulse lasers can also exhibit supercontinuum broadening and the generation of output spectra spanning 100’s of nm. Achieving these broadest bandwidths, however, requires careful optimization of the nonlinear polarization rotation based saturable absorber, which involves a very large potential parameter space. Here we study the spectral characteristics of a broadband noise-like pulse laser by scanning the laser operation over a random sample of 50,000 polarization settings, and we quantify that these broadest bandwidths are generated in only $$\sim$$ ∼ 0.5% of cases. We also show that a genetic algorithm can replace trial and error optimization to align the cavity for these broadband operating states.
TL;DR: In this paper , the authors report the generation of two-octave mid-infrared supercontinuum in stock, unprocessed, large core chalcogenide fiber pumped by a fiber-based laser delivering 35 kW, 180 fs pulses at 4.53 μm.
Abstract: We report on the generation of two-octave mid-infrared supercontinuum in stock, unprocessed, large core chalcogenide fiber pumped by a fiber-based laser delivering 35 kW, 180 fs pulses at 4.53 μm.
TL;DR: In this article , the dispersive wave (DW) emission from the Gaussian pulse with temporal sinusoidal phase (TSP) modulation was reported, which can effectively control the resonant frequency and energy conversion efficiency of the DW emission.
Abstract: We report the dispersive wave (DW) emission from the Gaussian pulse with temporal sinusoidal phase (TSP) modulation. The TSP-induced chirp can enhance or cancel the chirp generated by self-phase modulation by properly selecting the modulation parameters of TSP, which can influence the nonlinear propagation of the TSP-modulated pulse. It is shown that the TSP can effectively control the resonant frequency and energy conversion efficiency of the DW emission. We give a modified phase-matching condition to predict the resonant frequencies, which agree with the simulation results obtained by numerically solving the nonlinear Schrödinger equation. The enhanced conversion efficiency of the DWs can be increased up to 28% with only TSP modulation. Our results can extend the application of temporal phase modulation technology for wavelength conversion, and broadband supercontinuum generation.
TL;DR: In this paper , the authors investigated the nonlinear optical properties including third-and fifth-harmonic generation (THG and FHG) in thin layered PtS2 under infrared pump (1550-2510 nm).
Abstract: Nonlinear optical activities (e.g., harmonic generations) in two-dimensional (2D) layered materials have attracted much attention due to the great promise in diverse optoelectronic applications such as nonlinear optical modulators, nonreciprocal optical device, and nonlinear optical imaging. Exploration of nonlinear optical response (e.g., frequency conversion) in the infrared, especially the mid-infrared (MIR) region, is highly desirable for ultrafast MIR laser applications ranging from tunable MIR coherent sources, MIR supercontinuum generation, and MIR frequency-comb-based spectroscopy to high harmonic generation. However, nonlinear optical effects in 2D layered materials under MIR pump are rarely reported, mainly due to the lack of suitable 2D layered materials. Van der Waals layered platinum disulfide (PtS2) with a sizable bandgap from the visible to the infrared region is a promising candidate for realizing MIR nonlinear optical devices. In this work, we investigate the nonlinear optical properties including third-and fifth-harmonic generation (THG and FHG) in thin layered PtS2 under infrared pump (1550-2510 nm). Strikingly, the ultrastrong third-order nonlinear susceptibility χ(3)(-3ω;ω,ω,ω) of thin layered PtS2 in the MIR region was estimated to be over 10-18 m2/V2, which is about one order of that in traditional transition metal chalcogenides. Such excellent performance makes air-stable PtS2 a potential candidate for developing next-generation MIR nonlinear photonic devices.
TL;DR: In this article , the authors demonstrate the ability to generate a broad supercontinuum (SC) spectrum with a low peak power of square (S-PCF) and circular PCF lattice photonic crystal fibers with hollow core infiltrated with carbon tetrachloride (CCl4).
Abstract: 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.
TL;DR: In this paper , a high-average-power noise-like pulse (NLP) and dissipative soliton (DS) pulse fiber laser was proposed for supercontinuum generation and coherence tomography.
Abstract: We report a high-average-power noise-like pulse (NLP) and dissipative soliton (DS) pulse fiber laser. Average power as high as 4.8 W could be obtained at the fundamental mode-locked repetition rate. The NLP can also be transformed into a more powerful DS mode-locking state by optimizing the polarization and losses of intra-cavity pulses in the nonlinear polarization evolution regime. The operation mode between the NLP and DS can be switched, and the laser output performance in both modes has been studied. The main advantage of this work is switchable high-power operation between the NLP and DS. In comparison with conventional single-mode NLP fiber lasers, the multi-function high-power optical source will greatly push its application in supercontinuum generation, coherence tomography, and industrial processing.
TL;DR: In this paper , a hexagonal photonic crystal fiber (PCF) with a hollow core infiltrated with nitrobenzene (C6H5NO2) was demonstrated to generate a broad SC spectrum at low peak powers.
Abstract: 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.
TL;DR: In this article , a hyperspectral lidar with 64 spectral bands based on a supercontinuum light source using ray-tracing and 3D printing is developed to detect free-flying insects and their wingbeats.
Abstract: Monitoring insects of different species to understand the factors affecting their diversity and decline is a major challenge. Laser remote sensing and spectroscopy offer promising novel solutions to this. Coherent scattering from thin wing membranes also known as wing interference patterns (WIPs) have recently been demonstrated to be species specific. The colors of WIPs arise due to unique fringy spectra, which can be retrieved over long distances. To demonstrate this, a new concept of infrared (950–1650 nm) hyperspectral lidar with 64 spectral bands based on a supercontinuum light source using ray-tracing and 3D printing is developed. A lidar with an unprecedented number of spectral channels, high signal-to-noise ratio, and spatio-temporal resolution enabling detection of free-flying insects and their wingbeats. As proof of principle, coherent scatter from a damselfly wing at 87 m distance without averaging (4 ms recording) is retrieved. The fringed signal properties are used to determine an effective wing membrane thickness of 1412 nm with ±4 nm precision matching laboratory recordings of the same wing. Similar signals from free flying insects (2 ms recording) are later recorded. The accuracy and the method's potential are discussed to discriminate species by capturing coherent features from free-flying insects.
TL;DR: In this article , the authors demonstrate a wide-field hyperspectral mid-infrared (MIR) microscope based on multidimensional single-pixel imaging (SPI), which employs a high brightness MIR supercontinuum source for broadband (1.55 µm) sample illumination.
Abstract: In this contribution, we demonstrate a wide-field hyperspectral mid-infrared (MIR) microscope based on multidimensional single-pixel imaging (SPI). The microscope employs a high brightness MIR supercontinuum source for broadband (1.55 [Formula: see text]-4.5 [Formula: see text]) sample illumination. Hyperspectral imaging capability is achieved by a single micro-opto-electro-mechanical digital micromirror device (DMD), which provides both spatial and spectral differentiation. For that purpose the operational spectral bandwidth of the DMD was significantly extended into the MIR spectral region. In the presented design, the DMD fulfills two essential tasks. On the one hand, as standard for the SPI approach, the DMD sequentially masks captured scenes enabling diffraction-limited imaging in the tens of millisecond time-regime. On the other hand, the diffraction at the micromirrors leads to dispersion of the projected field and thus allows for wavelength selection without the application of additional dispersive optical elements, such as gratings or prisms. In the experimental part, first of all, the imaging and spectral capabilities of the hyperspectral microscope are characterized. The spatial and spectral resolution is assessed by means of test targets and linear variable filters, respectively. At a wavelength of 4.15 [Formula: see text] a spatial resolution of 4.92 [Formula: see text] is achieved with a native spectral resolution better than 118.1 nm. Further, a post-processing method for drastic enhancement of the spectral resolution is proposed and discussed. The performance of the MIR hyperspectral microsopce is demonstrated for label-free chemical imaging and examination of polymer compounds and red blood cells. The acquisition and reconstruction of Hadamard sampled 64 [Formula: see text] 64 images is achieved in 450 ms and 162 ms, respectively. Thus, combined with an unprecedented intrinsic flexibiliy gained by a tunable field of view and adjustable spatial resolution, the demonstrated design drastically improves the sample throughput in MIR chemical and biomedical imaging.
TL;DR: In this article , a self-referenced optical frequency comb (OFC) system was presented, which employs an allpolarization-maintained fiber figure-9 fiber oscillation as a seed laser, which is separated into two branches at the same repetition rate of approximately 100 MHz.
06 Mar 2023
TL;DR: In this article , the advantages and design limitations of singlemode, LMA, and PCF fiber laser sources are discussed, as well as methods to reach directly inaccessible wavelength ranges, maximize net efficiency, or shape the light inside of a fiber.
Abstract: The phrase "fiber laser" is a ubiquitous but insufficiently detailed description, as powers can range from microwatts to kilowatts. Fiber core diameters can vary from 3-micron core diameter ultra-high NA fibers for supercontinuum generation to 85 micron or greater PCF fibers to generate high pulse energies. With appropriate nonlinear optics, fiber lasers can reach wavelengths ranges from the UV to the LWIR and pulse widths can range from ultrafast femtosecond lasers to continuous output. The appropriate selection of laser can minimize cost, maximize efficiency, and ease assembly challenges in biomedical systems. The advantages and design limitations of single-mode, LMA, and PCF fiber lasers, as necessary to understand the available system impact of fiber laser source selection and including methods to reach directly inaccessible wavelength ranges, maximize net efficiency, or shape the light inside of a fiber are discussed.
TL;DR: In this article , a new square-lattice photonic crystal fiber (PCF) with a nitrobenzene core is presented, which allows the characteristic quantities to be optimized simultaneously to ensure near zero dispersion, a small effective mode area, and low loss for efficient spectral broadening.
Abstract: This study presents a new square-lattice photonic crystal fiber (PCF) with a nitrobenzene core. Considering the non-uniformity of the air hole diameter, this new design allows the characteristic quantities to be optimized simultaneously to ensure near-zero dispersion, a small effective mode area, and low loss for efficient spectral broadening. The spectrum broadens significantly at peak powers many times lower than in previous studies. Based on the obtained results, two optimal PCFs are proposed and validated in detail for supercontinuum generation (SCG). The first fiber #F1 operates in an all-normal dispersion regime with a pump wavelength of 1.3 µm.It produces a spectral supecontinuum (SC) from 0.726 to 1.649 µm with a pulse duration of 90 fs and a peak power of 133 W. Meanwhile, the second fiber #F2 operates in anomalous dispersion regime with a pump wavelength of 1.61 µm. With a low peak power of 300 W and a pulse duration of 150 fs, the fiber #F2 provides SC generation with bandwidth from 0.805 µm to 3.970 µm. The proposed fibers are suitable for all-fiber SC light sources, respectively, and may lead to new low-cost all-fiber optical systems.
TL;DR: In this article , a W-type fluorotellurite glass fiber was fabricated by rotational casting method, and the fiber has a small core of 5 μm in diameter with the lowest loss of 0.9 dB/m at 2.7 μm.
12 May 2023
TL;DR: In this paper , the role of rotational Raman response on the formation of flat supercontinuum was investigated in gas-filled anti-resonant guiding hollow-core photonic crystal fiber.
Abstract: We experimentally and numerically investigate flat supercontinuum generation in gas-filled anti-resonant guiding hollow-core photonic crystal fiber. By comparing results obtained with either argon or nitrogen we determine the role of the rotational Raman response on the supercontinuum formation. When using argon, a supercontinuum extending from 350 nm to 2 {\mu}m is generated through modulational instability. Although argon and nitrogen exhibit similar Kerr nonlinearity and dispersion, we find that the energy density of the continuum in the normal dispersion region is significantly lower when using nitrogen. Using numerical simulations, we find that due to the closely spaced rotational lines in nitrogen, gain suppression in the fundamental mode causes part of the pump pulse to be coupled into higher-order modes which reduces the energy transfer to wavelengths shorter than the pump.