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Showing papers on "Supercontinuum published in 2016"


Journal ArticleDOI
22 Jan 2016-Science
TL;DR: Using a continuous wave–pumped, dispersion-engineered, integrated silicon nitride microresonator, the device offers the opportunity to develop compact on-chip frequency combs for frequency metrology or spectroscopy.
Abstract: Optical solitons are propagating pulses of light that retain their shape because nonlinearity and dispersion balance each other. In the presence of higher-order dispersion, optical solitons can emit dispersive waves via the process of soliton Cherenkov radiation. This process underlies supercontinuum generation and is of critical importance in frequency metrology. Using a continuous wave-pumped, dispersion-engineered, integrated silicon nitride microresonator, we generated continuously circulating temporal dissipative Kerr solitons. The presence of higher-order dispersion led to the emission of red-shifted soliton Cherenkov radiation. The output corresponds to a fully coherent optical frequency comb that spans two-thirds of an octave and whose phase we were able to stabilize to the sub-Hertz level. By preserving coherence over a broad spectral bandwidth, our device offers the opportunity to develop compact on-chip frequency combs for frequency metrology or spectroscopy.

711 citations


Journal ArticleDOI
TL;DR: In this article, a new architecture for dual-comb spectroscopy based on all-fibre tunable frequency comb sources using standard telecommunication fibre optics components is proposed.
Abstract: Scientists propose and experimentally demonstrate a new architecture for dual-comb spectroscopy based on all-fibre tunable frequency comb sources using standard telecommunication fibre optics components, opening the way for practical dual-comb spectroscopy.

322 citations


Journal ArticleDOI
TL;DR: To the best of the knowledge, this is the broadest MIR SC generation observed so far in optical fibers and facilitates fiber-based applications in sensing, medical, and biological imaging areas.
Abstract: We experimentally demonstrate mid-infrared (MIR) supercontinuum (SC) generation spanning ∼2.0 to 15.1 μm in a 3 cm-long chalcogenide step-index fiber. The pump source is generated by the difference frequency generation with a pulse width of ∼170 fs, a repetition rate of ∼1000 Hz, and a wavelength range tunable from 2.4 to 11 μm. To the best of our knowledge, this is the broadest MIR SC generation observed so far in optical fibers. It facilitates fiber-based applications in sensing, medical, and biological imaging areas.

207 citations


Journal ArticleDOI
TL;DR: Efficient supercontinuum generation that extends into the visible spectral range by pumping a low differential mode group delay graded index multimode fiber in the normal dispersion regime is observed and could pave the way for high brightness, high power, and compact, multi-octave continuum sources.
Abstract: We observe efficient supercontinuum generation that extends into the visible spectral range by pumping a low differential mode group delay graded index multimode fiber in the normal dispersion regime. For a 28.5 m long fiber, the generated spectrum spans more than two octaves, starting from below 450 nm and extending beyond 2400 nm. The main nonlinear mechanisms contributing to the visible spectrum generation are attributed to multipath four-wave mixing processes and periodic spatio-temporal breathing dynamics. Moreover, by exploiting the highly multimodal nature of this system, we demonstrate versatile generation of visible spectral peaks in shorter fiber spans by altering the launching conditions. A nonlinearly induced mode cleanup was also observed at the pump wavelength. Our results could pave the way for high brightness, high power, and compact, multi-octave continuum sources.

193 citations


Journal ArticleDOI
05 Jun 2016
TL;DR: Applications to ultrafast fiber sources and connections to spatiotemporal modulation and conical wave instability are discussed and supercontinuum in graded-index multimode fibers is studied.
Abstract: We study supercontinuum in graded-index multimode fibers. Spatiotemporal oscillations of solitons produce radiation spanning from the mid-IR to ultraviolet. Applications to ultrafast fiber sources and connections to spatiotemporal modulation and conical wave instability are discussed.

160 citations


Journal ArticleDOI
TL;DR: The approximate shape of the fundamental pure-quartic soliton is derived and it is found that is surprisingly Gaussian, exhibiting excellent agreement with the experimental observations.
Abstract: Temporal optical solitons have been the subject of intense research due to their intriguing physics and applications in ultrafast optics and supercontinuum generation. Conventional bright optical solitons result from the interaction of anomalous group-velocity dispersion and self-phase modulation. Here we experimentally demonstrate a class of bright soliton arising purely from the interaction of negative fourth-order dispersion and self-phase modulation, which can occur even for normal group-velocity dispersion. We provide experimental and numerical evidence of shape-preserving propagation and flat temporal phase for the fundamental pure-quartic soliton and periodically modulated propagation for the higher-order pure-quartic solitons. We derive the approximate shape of the fundamental pure-quartic soliton and discover that is surprisingly Gaussian, exhibiting excellent agreement with our experimental observations. Our discovery, enabled by precise dispersion engineering, could find applications in communications, frequency combs and ultrafast lasers.

140 citations


Journal ArticleDOI
TL;DR: It is experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500 nm.
Abstract: We experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500 nm. We study the development of the supercontinuum along the multimode fiber by the cut-back method, which permits us to analyze the competition between the Kerr-induced geometric parametric instability and stimulated Raman scattering. We also performed a spectrally resolved temporal analysis of the supercontinuum emission.

117 citations


Journal ArticleDOI
20 Dec 2016
TL;DR: In this paper, the authors present an ultrafast mid-infrared fiber laser that uses holmium as the gain medium, which allows the central emission wavelength to shift to nearly 2.9μm and avoid the strong water vapor lines.
Abstract: The recent demonstrations of ultrafast mid-infrared fiber lasers emitting sub-picosecond pulses at 2.8 μm have created an exciting potential for a range of applications including mid-infrared frequency combs and materials processing. So far, this new class of laser has been based on the I11/24-I13/24 transition in erbium-doped fluoride fibers, which lies directly in a region of high water vapor absorption. This absorption has limited the achievable bandwidth, pulse duration, and peak power and poses a serious problem for transmission in free space. In this Letter, we present an ultrafast mid-infrared fiber laser that overcomes these limitations by using holmium as the gain medium. Holmium allows the central emission wavelength to shift to nearly 2.9 μm and avoid the strong water vapor lines. This laser, which represents the longest wavelength mode-locked fiber laser, emits 7.6 nJ pulses at 180 fs duration, with a record peak power of 37 kW. At this power level, the laser surpasses many commercial free-space OPA systems and becomes attractive for laser surgery of human tissue, for industrial materials modification, and for driving broadband coherent supercontinuum in the mid-infrared.

109 citations


Journal ArticleDOI
20 Sep 2016
TL;DR: In this paper, the authors reported a fiber-based system that generates femtosecond pulses with 5 nJ energy, continuously wavelength-tunable over 2.3 μm through the soliton self-frequency shift (SSFS) in fluoride fibers.
Abstract: There is great interest in sources of coherent radiation in the mid-wave infrared (3–5 μm), and instruments based on fiber can offer major practical advantages. This range, and much broader, can be covered easily by supercontinuum generation in soft glass fibers, but with low power spectral density. For applications that require intense ultrashort pulses, fiber sources are quite limited. In this Letter, we report a fiber-based system that generates 100 fs pulses with 5 nJ energy, continuously wavelength-tunable over 2–4.3 μm through the soliton self-frequency shift (SSFS) in fluoride fibers. The pulse energies are 2 orders of magnitude higher than those previously achieved by SSFS, around 3 μm, and the range of wavelengths is extended by 1000 nm. Peak power ranges from 20 to 75 kW are achieved across the tuning range. Numerical simulations are in good agreement with the experimental results, and indicate the potential for few-cycle soliton generation out to 5.6 μm. Fiber-integrated sources of femtosecond pulses tunable across this region should be valuable for mid-infrared applications.

108 citations


Journal ArticleDOI
TL;DR: It is reported the coherent mid-infrared supercontinuum generation in an all-solid chalcogenide microstructured fiber with all-normal dispersion with a four-hole structure with core material of AsSe2 and air holes that are replaced by As2S5 glass rods.
Abstract: We report the coherent mid-infrared supercontinuum generation in an all-solid chalcogenide microstructured fiber with all-normal dispersion. The chalcogenide microstructured fiber is a four-hole structure with core material of AsSe2 and air holes that are replaced by As2S5 glass rods. Coherent mid-infrared supercontinuum light extended to 3.3 μm is generated in a 2 cm long chalcogenide microstructured fiber pumped by a 2.7 μm laser.

102 citations


Journal ArticleDOI
TL;DR: This Letter reports the production of a supercontinuum extending from ≈2 μm to >10‬‬μm generated using a chalcogenide buried rib waveguide pumped with 330 femtosecond pulses at 4.184 μm, which is, to the best of the authors' knowledge, the broadest mid-infraredsupercontinuum generated in any planar waveguide platform.
Abstract: This Letter reports the production of a supercontinuum extending from ≈2 μm to >10 μm generated using a chalcogenide buried rib waveguide pumped with 330 femtosecond pulses at 4.184 μm. This is, to the best of our knowledge, the broadest mid-infrared supercontinuum generated in any planar waveguide platform. Because the waveguide is birefringent, quasi-single-mode, and uses an optimized dispersion design, the supercontinuum is linearly polarized with an extinction ratio >100. Dual beam spectrophotometry is performed easily using this source.

Journal ArticleDOI
TL;DR: The first successful frequency comb offset stabilization that utilizes a Si3N4 waveguide for octave-spanning supercontinuum generation and achieve the lowest integrated residual phase noise of any diode-pumped gigahertz laser comb to date is demonstrated.
Abstract: Silicon nitride (Si3N4) waveguides represent a novel photonic platform that is ideally suited for energy efficient and ultrabroadband nonlinear interactions from the visible to the mid-infrared. Chip-based supercontinuum generation in Si3N4 offers a path towards a fully-integrated and highly compact comb source for sensing and time-and-frequency metrology applications. We demonstrate the first successful frequency comb offset stabilization that utilizes a Si3N4 waveguide for octave-spanning supercontinuum generation and achieve the lowest integrated residual phase noise of any diode-pumped gigahertz laser comb to date. In addition, we perform a direct comparison to a standard silica photonic crystal fiber (PCF) using the same ultrafast solid-state laser oscillator operating at 1 µm. We identify the minimal role of Raman scattering in Si3N4 as a key benefit that allows to overcome the fundamental limitations of silica fibers set by Raman-induced self-frequency shift.

Journal ArticleDOI
TL;DR: In this paper, an environment friendly nonlinear chalcogenide glass fiber with a Ge-Sb-Se core and a ge-Se cladding is fabricated for bright broadband mid-infrared (MIR) supercontinuum (SC) generation.
Abstract: An environment friendly nonlinear chalcogenide glass fiber with a Ge-Sb-Se core and a Ge-Se cladding is fabricated for bright broadband mid-infrared (MIR) supercontinuum (SC) generation. The fabricated Ge-Sb-Se/Ge-Se fiber with a core diameter of 6 μm shows zero group velocity dispersion at ~4.2 μm and ~7.3 μm. By pumping the fiber with a length of 11 cm at 4.485 μm with 330 fs pulses, we achieve a SC covering the 2.2–12 μm spectral range and with an output average power of ~17 mW. This bright broadband SC source is promising for high-resolution MIR spectroscopy.

Journal ArticleDOI
TL;DR: It is shown that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures, determined by nonlocality of the electron response.
Abstract: Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response.


Journal ArticleDOI
TL;DR: A mid-infrared supercontinuum extending up to 5.4 μm is generated in a low-loss fluoroindate fiber with more than 82% of the total power beyond 3 μm, promising for efficient mid-IR light generation.
Abstract: A mid-infrared supercontinuum extending up to 5.4 μm is generated in a low-loss fluoroindate fiber. It is pumped with an erbium-doped fluoride fiber amplifier seeded with 400 ps pulses at 2.75 μm. Both fibers are fusion spliced to increase the robustness and long-term stability of the system. With more than 82% of the total power beyond 3 μm, this approach is promising for efficient mid-IR light generation.

Journal ArticleDOI
TL;DR: A novel high nonlinear fiber made of Ge-Sb-Se chalcogenide glasses with high numerical aperture is fabricated and supercontinuum spanning from ∼1.8 to ∼14 μm was generated.
Abstract: We report the fabrication of a novel high nonlinear fiber made of Ge-Sb-Se chalcogenide glasses with high numerical aperture (∼1.0), where the core and the cladding glasses consist of Ge15Sb25Se60 and Ge15Sb20Se65 (mol. %), respectively. The nonlinear refractive index (n2) of the core glass is 19×10-18 m2/W at 1.55 μm, and its laser-induced damage threshold under irradiation of 3.0 μm fs laser is approximately 3674 GW/cm2. By pumping a 20-cm-long fiber with a core diameter of 23 μm using 150 fs pulses at 6.0 μm, supercontinuum spanning from ∼1.8 to ∼14 μm was generated.

Journal ArticleDOI
TL;DR: To the best of the knowledge, this is the first SC experimental demonstration in Te-based ChG fiber and the broadest MIR SC generation pumped in the normal dispersion regime in the optical fibers.
Abstract: We have experimentally demonstrated midinfrared (MIR) supercontinuum (SC) generation in a low-loss Te-based chalcogenide (ChG) step-index fiber. The fiber, fabricated by an isolated extrusion method, has an optical loss of 2–3 dB/m at 6.2–10.3 μm and 3.2 dB/m at 10.6 μm, the lowest value reported for any Te-based ChG step-index fiber. A MIR SC spectrum (∼1.5 to 14 μm) is generated from the 23-cm fiber pumped by a 4.5 μm laser (∼150 fs, 1 kHz). To the best of our knowledge, this is the first SC experimental demonstration in Te-based ChG fiber and the broadest MIR SC generation pumped in the normal dispersion regime in the optical fibers.

Journal ArticleDOI
TL;DR: The chalcogen glasses (i.e., glasses based on the elements S, Se, and Te) are transparent in the infrared (IR), possess low phonon energies, are chemically durable, and can be drawn into fiber as discussed by the authors.
Abstract: The chalcogen glasses (i.e., glasses based on the elements S, Se, and Te) are transparent in the infrared (IR), possess low phonon energies, are chemically durable, and can be drawn into fiber. We review our recent research progress at the Naval Research Laboratory (NRL) to develop chalcogenide glass fibers for applications in the mid- and long-wave IR wavelength regions from 2 to 12 μm. Our recent effort in the development of low loss chalcogenide fibers, by describing the synthesis and purification methods, fiber drawing techniques, and highlighting the best results, is summarized. Various applications of these high quality chalcogenide fibers, including multimode beam combiners, mid-infrared supercontinuum sources, fiber Bragg gratings, fiber bundles for IR imaging, anti-reflecting surface structures, and modal filters, are described. Novel infrared (IR) lenses that enable a reduction in the size and weight of IR imaging optics through the use of layered glass structures with broad IR transmission are also presented.

Journal ArticleDOI
TL;DR: Experimental evidence and numerical simulations are presented confirming that the spectral-temporal composition of the pump continuum is critical for continued broadening in a chalcogenide fiber and a commercially viable fiber-cascading configuration is presented to generate a mid-infrared supercontinuum up to 7 μm in commercial chalCogenide fibers.
Abstract: Supercontinuum generation in chalcogenide fibers is a promising technology for broadband spatially coherent sources in the mid-infrared, but it suffers from discouraging commercial prospects, mainly due to a lack of suitable pump lasers. Here, a promising approach is experimentally demonstrated using an amplified 1.55 μm diode laser to generate a pump continuum up to 4.4 μm in cascaded silica and fluoride fibers. We present experimental evidence and numerical simulations confirming that the spectral-temporal composition of the pump continuum is critical for continued broadening in a chalcogenide fiber. The fundamental physical question is concerned with the long-wavelength components of the pump spectrum, which may consist of either solitons or dispersive waves. In demonstrating this we present a commercially viable fiber-cascading configuration to generate a mid-infrared supercontinuum up to 7 μm in commercial chalcogenide fibers.

Journal ArticleDOI
TL;DR: The modeling indicates that when only a single polarisation in the fundamental mode is considered the obtainable supercontinuum bandwidth is substantially exaggerated compared to when both polarisations are taken into account.
Abstract: Mid-infrared supercontinuum generation is considered in chalcogenide fibres when taking into account both polarisations and the necessary higher order modes. In particular we focus on high pulse energy supercontinuum generation with long pump pulses. The modeling indicates that when only a single polarisation in the fundamental mode is considered the obtainable supercontinuum bandwidth is substantially exaggerated compared to when both polarisations are taken into account. Our modeling shows that if the pump pulse is short enough (≤ 10ps) then higher order modes are not important because of temporal walk-off. In contrast long pump pulses (≥ 40ps) will efficiently excite higher order modes through Raman scattering, which will deplete the fundamental mode of energy and limit the possibility of obtaining a broadband supercontinuum.

Journal ArticleDOI
TL;DR: In this paper, a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500nm.
Abstract: We experimentally demonstrate that pumping a graded-index multimode fiber with sub-ns pulses from a microchip Nd:YAG laser leads to spectrally flat supercontinuum generation with a uniform bell-shaped spatial beam profile extending from the visible to the mid-infrared at 2500\,nm. We study the development of the supercontinuum along the multimode fiber by the cut-back method, which permits us to analyze the competition between the Kerr-induced geometric parametric instability and stimulated Raman scattering. We also performed a spectrally resolved temporal analysis of the supercontinuum emission.

Journal ArticleDOI
TL;DR: In this article, the polarization gating technique with a two-cycle, 1.7μm driving field was used to generate an attosecond supercontinuum extending to the water window spectral region.
Abstract: We implement the polarization gating (PG) technique with a two-cycle, 1.7 μm driving field to generate an attosecond supercontinuum extending to the water window spectral region. The ellipticity dependence of the high harmonic yield over a photon energy range much broader than previous work is measured and compared with a semi-classical model. When PG is applied, the carrier-envelope phase (CEP) is swept to study its influence on the continuum generation. PG with one-cycle (5.7 fs) and two-cycle (11.3 fs) delay are tested, and both give continuous spectra spanning from 50 to 450 eV under certain CEP values, strongly indicating the generation of isolated attosecond pulses in the water window region.

Journal ArticleDOI
TL;DR: A silica-based anti-resonant hollow-core fiber which has good guidance properties in the mid-IR filled with supercritical xenon providing the necessary high nonlinearity is studied, showing that by launching a 200 nJ pump of 100 fs centered at 3.70 μm, a supercontinuum can be generated.
Abstract: We present an investigation on the generation of supercontinuum in the mid-infrared (mid-IR) spectral region Namely, we study a silica-based anti-resonant hollow-core fiber which has good guidance properties in the mid-IR filled with supercritical xenon providing the necessary high nonlinearity Our numerical study shows that by launching a 200 nJ pump of 100 fs centered at 370 μm, a supercontinuum that spans from 185 to 520 μm can be generated Such sources are potentially useful for applications, such as the remote sensing of various molecules, medical imaging diagnosis, and surgery

Journal ArticleDOI
TL;DR: An experimental assessment of the shot-to-shot noise performance of supercontinuum generation in two types of soft glass photonic crystal fibers in the cases of an anomalous dispersion-pumped fiber and an all-normal dispersion fiber is provided.
Abstract: Coherence of supercontinuum sources is critical for applications involving characterization of ultrafast or rarely occurring phenomena. With the demonstrated spectral coverage of supercontinuum extending from near-infrared to over 10 μm in a single nonlinear fiber, there has been a clear push for the bandwidth rather than for attempting to optimize the dynamic properties of the generated spectrum. In this work we provide an experimental assessment of the shot-to-shot noise performance of supercontinuum generation in two types of soft glass photonic crystal fibers. Phase coherence and intensity fluctuations are compared for the cases of an anomalous dispersion-pumped fiber and an all-normal dispersion fiber. With the use of the dispersive Fourier transformation method, we demonstrate that a factor of 100 improvement in signal-to-noise ratio is achieved in the normal-dispersion over anomalous dispersion-pumped fiber for 390 fs long pump pulses. A double-clad design of the photonic lattice of the fiber is further postulated to enable a pump-related seeding mechanism of normal-dispersion supercontinuum broadening under sub-picosecond pumping, which is otherwise known for similar noise characteristics as modulation instability driven, soliton-based spectra.

Journal ArticleDOI
TL;DR: The performance of the SC-based SD-OCT endoscopy system was demonstrated by imaging guinea pig esophagus in vivo, achieving image quality comparable to that acquired with a broadband home-built Ti:sapphire laser.
Abstract: We investigated the optimal operational conditions for utilizing a broadband supercontinuum (SC) source in a portable 800 nm spectral-domain (SD) endoscopic OCT system to enable high resolution, high-sensitivity, and high-speed imaging in vivo. A SC source with a 3-dB bandwidth of ∼246 nm was employed to obtain an axial resolution of ∼2.7 μm (in air) and an optimal detection sensitivity of ∼-107 dB with an imaging speed up to 35 frames/s (at 70 k A-scans/s). The performance of the SC-based SD-OCT endoscopy system was demonstrated by imaging guinea pig esophagus in vivo, achieving image quality comparable to that acquired with a broadband home-built Ti:sapphire laser.

Journal ArticleDOI
TL;DR: In this paper, a supercontinuum (SC) light source generated by noise-like pulses from an Yb-doped fiber laser was used for OCT imaging of bio-tissue.
Abstract: We report on the ultrahigh-resolution optical coherence tomography (OCT) with a novel high-power supercontinuum (SC) light source generated by noise-like pulses from an Yb-doped fiber laser. The SC spectrum is flat with a bandwidth of 420 nm centered around ~1.3 μm. The light source is successfully employed in a time-domain OCT (TD-OCT), achieving an axial resolution of 2.3 μm. High resolution fiber-based spectral-domain OCT (SD-OCT) imaging of bio-tissue was also demonstrated.

Journal ArticleDOI
TL;DR: A TA spectrophotometer in which there is no synchronization between a pump pulse and a train of multiple probe pulses from a picosecond supercontinuum light source is proposed, termed the randomly-interleaved-pulse-train (RIPT) method.
Abstract: Despite the long-standing importance of transient absorption (TA) spectroscopy, many researchers remain frustrated by the difficulty of measuring the nanosecond range in a wide spectral range. To address this shortcoming, we propose a TA spectrophotometer in which there is no synchronization between a pump pulse and a train of multiple probe pulses from a picosecond supercontinuum light source, termed the randomly-interleaved-pulse-train (RIPT) method. For each pump pulse, many monochromatized probe pulses impinge upon the sample, and the associated pump-probe time delays are determined passively shot by shot with subnanosecond accuracy. By repeatedly pumping with automatically varying time delays, a TA temporal profile that covers a wide dynamic range from subnanosecond to milliseconds is simultaneously obtained. By scanning wavelength, this single, simple apparatus acquires not only wide time range TA profiles, but also broadband TA spectra from the visible through the near-infrared regions. Furthermore, we present a typical result to demonstrate how the RIPT method may be used to correct for fluorescence, which often pollutes TA curves.

Journal ArticleDOI
TL;DR: In this paper, an octave-spanning supercontinuum generation in a nonstoichiometric silicon-rich nitride waveguide was demonstrated by femtosecond pulses from an erbium fiber laser.
Abstract: We experimentally show octave-spanning supercontinuum generation in a nonstoichiometric silicon-rich nitride waveguide when pumped by femtosecond pulses from an erbium fiber laser. The pulse energy and bandwidth are comparable to results achieved in stoichiometric silicon nitride waveguides, but our material platform is simpler to manufacture. We also observe wave-breaking supercontinuum generation by using orthogonal pumping in the same waveguide. Additional analysis reveals that the waveguide height is a powerful tuning parameter for generating mid-infrared dispersive waves while keeping the pump in the telecom band.

Journal ArticleDOI
TL;DR: The presented source might serve as a pump for supercontinuum generation in highly nonlinear fibers in a Tm-doped fiber laser mode-locked by multilayer graphene saturable absorber.
Abstract: We report on the generation of noise-like pulse (NLP) trains in a Tm-doped fiber laser mode-locked by multilayer graphene saturable absorber. The spectral bandwidth obtained directly from the oscillator exceeds 60 nm, centered at 1950 nm, with 23.5 MHz repetition rate. The pulses were also amplified in a fully fiberized amplifier based on a double-cladding Tm-doped fiber. The system was capable of delivering 1.21 W of average power, which corresponds to 51.5 nJ energy stored in the noise-like bundle. We believe that the presented source might serve as a pump for supercontinuum generation in highly nonlinear fibers.