We demonstrate experimentally and theoretically that the core-guided mode in helically twisted photonic crystal fiber exhibits resonantly enhanced optical activity and circular dichroism in the vicinity of anti-crossings with leaky orbital angular momentum (OAM) modes in the cladding. This arises because the anti-crossings for left and right circularly polarized core modes occur at slightly different wavelengths. (C) 2015 Optical Society of America
Photoionization-Induced Emission of Tunable Few-Cycle Midinfrared
Dispersive Waves in Gas-Filled Hollow-Core Photonic Crystal Fibers
D. Novoa,
M. Cassataro,
J. C. Travers,
P. St. J. Russell
We propose a scheme for the emission of few-cycle dispersive waves in the midinfrared using hollow-core photonic crystal fibers filled with noble gas. The underlying mechanism is the formation of a plasma cloud by a self-compressed, subcycle pump pulse. The resulting free-electron population modifies the fiber dispersion, allowing phase-matched access to dispersive waves at otherwise inaccessible frequencies, well into the midinfrared. Remarkably, the pulses generated turn out to have durations of the order of two optical cycles. In addition, this ultrafast emission, which occurs even in the absence of a zero dispersion point between pump and midinfrared wavelengths, is tunable over a wide frequency range simply by adjusting the gas pressure. These theoretical results pave the way to a new generation of compact, fiber-based sources of few-cycle midinfrared radiation.
Phase-matched electric-field-induced second-harmonic generation in
Xe-filled hollow-core photonic crystal fiber
Second-order nonlinearity is induced inside a Xe-filled hollow-core photonic crystal fiber (PCF) by applying an external dc field. The system uniquely allows the linear optical properties to be adjusted by changing the gas pressure, allowing for precise phase matching between the LP01 mode at 1064 nm and the LP02 mode at 532 nm. The dependence of the second-harmonic conversion efficiency on the gas pressure, launched pulse energy, and applied field agrees well with theory. The ultra-broadband guidance offered by anti-resonant reflecting hollow-core PCFs, for example, a kagome PCF, offers many possibilities for generating light in traditionally difficult-to-access regions of the electromagnetic spectrum, such as the ultraviolet or the terahertz windows. The system can also be used for non-invasive measurements of the transmission loss in a hollow-core PCF over a broad spectrum, including the deep and vacuum UV regions. (C) 2015 Optical Society of America
Raman-Free, Noble-Gas-Filled Photonic-Crystal Fiber Source for
Ultrafast, Very Bright Twin-Beam Squeezed Vacuum
Martin A. Finger,
Timur Sh. Iskhakov,
Nicolas Y. Joly,
Maria V. Chekhova,
Philip St. J. Russell
We report a novel source of twin beams based on modulational instability in high-pressure argon-filled hollow-core kagome-style photonic-crystal fiber. The source is Raman-free and manifests strong photonnumber correlations for femtosecond pulses of squeezed vacuum with a record brightness of similar to 2500 photons per mode. The ultra-broadband (similar to 50 THz) twin beams are frequency tunable and contain one spatial and less than 5 frequency modes. The presented source outperforms all previously reported squeezed-vacuum twin-beam sources in terms of brightness and low mode content.
Giant Optical Activity of Quantum Dots, Rods, and Disks with Screw
Dislocations
Anvar S. Baimuratov,
Ivan D. Rukhlenko,
Roman E. Noskov,
Pavel Ginzburg,
Yurii K. Gun'ko,
Alexander V. Baranov,
Anatoly V. Fedorov
For centuries mankind has been modifying the optical properties of materials: first, by elaborating the geometry and composition of structures made of materials found in nature, later by structuring the existing materials at a scale smaller than the operating wavelength. Here we suggest an original approach to introduce optical activity in nanostructured materials, by theoretically demonstrating that conventional achiral semiconducting nanocrystals become optically active in the presence of screw dislocations, which can naturally develop during the nanocrystal growth. We show the new properties to emerge due to the dislocation-induced distortion of the crystal lattice and the associated alteration of the nanocrystal's electronic subsystem, which essentially modifies its interaction with external optical fields. The g-factors of intraband transitions in our nanocrystals are found comparable with dissymmetry factors of chiral plasmonic complexes, and exceeding the typical g-factors of chiral molecules by a factor of 1000. Optically active semiconducting nanocrystals-with chiral properties controllable by the nanocrystal dimensions, morphology, composition and blending ratio-will greatly benefit chemistry, biology and medicine by advancing enantiomeric recognition, sensing and resolution of chiral molecules.
Flying particle sensors in hollow-core photonic crystal fibre
D. S. Bykov,
O. A. Schmidt,
T. G. Euser,
P. St. J. Russell
Optical fibre sensors make use of diverse physical effects to measure parameters such as strain, temperature and electric field. Here we introduce a new class of reconfigurable fibre sensor, based on a 'flying-particle' optically trapped inside a hollow-core photonic crystal fibre and illustrate its use in electric field and temperature sensing with high spatial resolution. The electric field distribution near the surface of a multi-element electrode is measured with a resolution of similar to 100 mu m by monitoring changes in the transmitted light signal due to the transverse displacement of a charged silica microparticle trapped within the hollow core. Doppler-based velocity measurements are used to map the gas viscosity, and thus the temperature, along a hollow-core photonic crystal fibre. The flying-particle approach represents a new paradigm in fibre sensors, potentially allowing multiple physical quantities to be mapped with high positional accuracy over kilometre-scale distances.
Generation of three-octave-spanning transient Raman comb in
hydrogen-filled hollow-core PCF
F. Tani,
F. Belli,
A. Abdolvand,
J. C. Travers,
P. St. J. Russell
A noise-seeded transient comb of Raman sidebands spanning three octaves from 180 to 2400 nm, is generated by pumping a hydrogen-filled hollow-core photonic crystal fiber with 26-mu J, 300-fs pulses at 800 nm. The pump pulses are spectrally broadened by both Kerr and Raman-related self-phase modulation (SPM), and the broadening is then transferred to the Raman lines. In spite of the high intensity, and in contrast to bulk gas-cell based experiments, neither SPM broadening nor ionization are detrimental to comb formation. (C) 2015 Optical Society of America
Deep-ultraviolet to mid-infrared supercontinuum generated in solid-core ZBLAN photonic crystal fibre
Xin Jiang,
Nicolas Y. Joly,
Martin A. Finger,
Fehim Babic,
Gordon K. L. Wong,
John C. Travers,
Philip St J. Russell
Silica-based photonic crystal fibre has proven highly successful for supercontinuum generation, with smooth and flat spectral power densities. However, fused silica glass suffers from strong material absorption in the mid-infrared (>2,500 nm), as well as ultraviolet-related optical damage (solarization), which limits performance and lifetime in the ultraviolet (<380 nm). Supercontinuum generation in silica photonic crystal fibre is therefore only possible between these limits. A number of alternative glasses have been used to extend the mid-infrared performance, including chalcogenides, fluorides and heavy-metal oxides, but none has extended the ultraviolet performance. Here, we describe the successful fabrication (using the stack-and-draw technique) of a ZBLAN photonic crystal fibre with a high air-filling fraction, a small solid core, nanoscale features and near-perfect structure. We also report its use in the generation of ultrabroadband, long-term stable, supercontinua spanning more than three octaves in the spectral range 200-2,500 nm.
Compressing mu J-level pulses from 250 fs to sub-10 fs at 38-MHz
repetition rate using two gas-filled hollow-core photonic crystal fiber
stages
K. F. Mak,
M. Seidel,
O. Pronin,
M. H. Frosz,
A. Abdolvand,
V. Pervak,
A. Apolonski,
F. Krausz,
J. C. Travers, et al.
Compression of 250-fs, 1-mu J pulses from a KLM Yb:YAG thin-disk oscillator down to 9.1 fs is demonstrated. A kagome-PCF with a 36-mu m core-diameter is used with a pressure gradient from 0 to 40 bar of krypton. Compression to 22 fs is achieved by 1200 fs(2) group-delay-dispersion provided by chirped mirrors. By coupling the output into a second kagome-PCF with a pressure gradient from 0 to 25 bar of argon, octave spanning spectral broadening via the soliton-effect is observed at 18-W average output power. Self-compression to 9.1 fs is measured, with compressibility to 5 fs predicted. Also observed is strong emission in the visible via dispersive wave generation, amounting to 4% of the total output power. (C) 2015 Optical Society of America
Modulational instability windows in the nonlinear Schrodinger equation
involving higher-order Kerr responses
David Novoa,
Daniele Tommasini,
Jose A. Novoa-Lopez
We introduce a complete analytical and numerical study of the modulational instability process in a system governed by a canonical nonlinear Schrodinger equation involving local, arbitrary nonlinear responses to the applied field. In particular, our theory accounts for the recently proposed higher-order Kerr nonlinearities, providing very simple analytical criteria for the identification of multiple regimes of stability and instability of plane-wave solutions in such systems. Moreover, we discuss a new parametric regime in the higher-order Kerr response, which allows for the observation of several, alternating stability-instability windows defining a yet unexplored instability landscape.
Position-Squared Coupling in a Tunable Photonic Crystal Optomechanical
Cavity
Taofiq K. Paraiso,
Mahmoud Kalaee,
Leyun Zang,
Hannes Pfeifer,
Florian Marquardt,
Oskar Painter
Physical Review X
5
(4)
041024
(2015)
| Journal
| PDF
We present the design, fabrication, and characterization of a planar silicon photonic crystal cavity in which large position-squared optomechanical coupling is realized. The device consists of a double-slotted photonic crystal structure in which motion of a central beam mode couples to two high-Q optical modes localized around each slot. Electrostatic tuning of the structure is used to controllably hybridize the optical modes into supermodes that couple in a quadratic fashion to the motion of the beam. From independent measurements of the anticrossing of the optical modes and of the dynamic optical spring effect, a position-squared vacuum coupling rate as large as (g) over tilde'/2 pi = 245 Hz is inferred between the optical supermodes and the fundamental in-plane mechanical resonance of the structure at omega(m)/2 pi = 8.7 MHz, which in displacement units corresponds to a coupling coefficient of g'/2 pi = 1 THz/nm(2). For larger supermode splittings, selective excitation of the individual optical supermodes is used to demonstrate optical trapping of the mechanical resonator with measured (g) over tilde'/2 pi = 46 Hz.
Broadband-tunable LP01 mode frequency shifting by Raman coherence waves
in a H-2-filled hollow-core photonic crystal fiber
S. T. Bauerschmidt,
D. Novoa,
A. Abdolvand,
P. St. J. Russell
When a laser pump beam of sufficient intensity is incident on a Raman-active medium such as hydrogen gas, a strong Stokes signal, redshifted by the Raman transition frequency Omega(R), is generated. This is accompanied by the creation of a "coherence wave" of synchronized molecular oscillations with wave vector Delta beta determined by the optical dispersion. Within its lifetime, this coherence wave can be used to shift by Omega(R) the frequency of a third "mixing" signal, provided phase matching is satisfied, i.e., Delta beta is matched. Conventionally, this can be arranged using noncollinear beams or higher-order waveguide modes. Here we report the collinear phase-matched frequency shifting of an arbitrary mixing signal using only the fundamental LP01 modes of a hydrogen-filled hollow-core photonic crystal fiber. This is made possible by the S-shaped dispersion curve that occurs around the pressure-tunable zero dispersion point. Phase-matched frequency shifting by 125 THz is possible from the UV to the near IR. Long interaction lengths and tight modal confinement reduce the peak intensities required, allowing conversion efficiencies in excess of 70%. The system is of great interest in coherent anti-Stokes Raman spectroscopy and for wavelength conversion of broadband laser sources. (C) 2015 Optical Society of America
Angle-resolved photoemission spectroscopy with 9-eV photon-energy pulses
generated in a gas-filled hollow-core photonic crystal fiber
H. Bromberger,
A. Ermolov,
F. Belli,
H. Liu,
F. Calegari,
M. Chavez-Cervantes,
M. T. Li,
C. T. Lin,
A. Abdolvand, et al.
A recently developed source of ultraviolet radiation, based on optical soliton propagation in a gasfilled hollow-core photonic crystal fiber, is applied here to angle-resolved photoemission spectroscopy (ARPES). Near-infrared femtosecond pulses of only few mu J energy generate vacuum ultraviolet radiation between 5.5 and 9 eV inside the gas-filled fiber. These pulses are used to measure the band structure of the topological insulator Bi2Se3 with a signal to noise ratio comparable to that obtained with high order harmonics from a gas jet. The two-order-of-magnitude gain in efficiency promises time-resolved ARPES measurements at repetition rates of hundreds of kHz or even MHz, with photon energies that cover the first Brillouin zone of most materials. (C) 2015 AIP Publishing LLC.
Microcavity design for low threshold polariton condensation with
ultrashort optical pulse excitation
C. Poellmann,
U. Leierseder,
E. Galopin,
A. Lemaitre,
A. Amo,
J. Bloch,
R. Huber,
J. -M. Menard
JOURNAL OF APPLIED PHYSICS
117
(20)
205702
(2015)
| Journal
We present a microcavity structure with a shifted photonic stop-band to enable efficient non-resonant injection of a polariton condensate with spectrally broad femtosecond pulses. The concept is demonstrated theoretically and confirmed experimentally for a planar GaAs/AlGaAs multilayer heterostructure pumped with ultrashort near-infrared pulses while photoluminescence is collected to monitor the optically injected polariton density. As the excitation wavelength is scanned, a regime of polariton condensation can be reached in our structure at a consistently lower fluence threshold than in a state-of-the-art conventional microcavity. Our microcavity design improves the polariton injection efficiency by a factor of 4, as compared to a conventional microcavity design, when broad excitation pulses are centered at a wavelength of lambda = 740 nm. Most remarkably, this improvement factor reaches 270 when the excitation wavelength is centered at 750 nm. (c) 2015 AIP Publishing LLC.
Supercontinuum generation in the vacuum ultraviolet through dispersive-wave and soliton-plasma interaction in a noble-gas-filled hollow-core photonic crystal fiber
A. Ermolov,
K. F. Mak,
M. H. Frosz,
J. C. Travers,
P. St. J. Russell
We report on the generation of a three-octave-wide supercontinuum extending from the vacuum ultraviolet (VUV) to the near infrared, spanning at least 113-1000 nm (i.e., 11-1.2eV), in He-filled hollow-core kagome-style photonic crystal fiber. Numerical simulations confirm that the main mechanism is an interaction between dispersive-wave emission and plasma-induced blue-shifted soliton recompression around the fiber zero dispersion frequency. The VUV part of the supercontinuum, the modeling of which proves to be coherent and possesses a simple phase structure, has sufficient bandwidth to support single-cycle pulses of 500 asec duration. We also demonstrate, in the same system, the generation of narrower-band VUV pulses through dispersive-wave emission, tunable from 120 to 200 nm with efficiencies exceeding 1% and VUV pulse energies in excess of 50 nJ.
Vacuum-ultraviolet to infrared supercontinuum in hydrogen-filled
photonic crystal fiber
Federico Belli,
Amir Abdolvand,
Wonkeun Chang,
John C. Travers,
Philip St. J. Russell
Although supercontinuum sources are readily available for the visible and near infrared (IR), and recently also for the mid-IR, many areas of biology, chemistry, and physics would benefit greatly from the availability of compact, stable, and spectrally bright deep-ultraviolet and vacuum-ultraviolet (VUV) supercontinuum sources. Such sources have, however, not yet been developed. Here we report the generation of a bright supercontinuum, spanning more than three octaves from 124 nm to beyond 1200 nm, in hydrogen-filled kagome-style hollow-core photonic crystal fiber (kagome-PCF). Few-microjoule, 30 fs pump pulses at wavelength of 805 nm are launched into the fiber, where they undergo self-compression via the Raman-enhanced Kerr effect. Modeling indicates that before reaching a minimum subcycle pulse duration of similar to 1 fs, much less than one period of molecular vibration (8 fs), nonlinear reshaping of the pulse envelope, accentuated by self-steepening and shock formation, creates an ultrashort feature that causes impulsive excitation of long-lived coherent molecular vibrations. These phase modulate a strong VUV dispersive wave (at 182 nm or 6.8 eV) on the trailing edge of the pulse, further broadening the spectrum into the VUV. The results also show for the first time that kagome-PCF guides well in the VUV. (C) 2015 Optical Society of America
Dissipative plasmon solitons in graphene nanodisk arrays
Daria A. Smirnova,
Roman E. Noskov,
Lev A. Smirnov,
Yuri S. Kivshar
We study nonlinear modes in arrays of doped graphene nanodisks with Kerr-type nonlinear response in the presence of an external electric field. We introduce a theoretical model describing the evolution of the nanodisks' polarizations taking into account intrinsic graphene losses and dipole-dipole coupling between the graphene nanodisks. We reveal that this nonlinear system can support discrete dissipative scalar solitons of both longitudinal and transverse polarizations, as well as vector solitons composed of two mutually coupled polarization components. We demonstrate the formation of stable resting and moving localized modes in this discrete model under controlling guidance of the external driving field.
An ion trap built with photonic crystal fibre technology
F. Lindenfelser,
B. Keitch,
D. Kienzler,
D. Bykov,
P. Uebel,
M. A. Schmidt,
P. St. J. Russell,
J. P. Home
REVIEW OF SCIENTIFIC INSTRUMENTS
86
(3)
033107
(2015)
| Journal
We demonstrate a surface-electrode ion trap fabricated using techniques transferred from the manufacture of photonic-crystal fibres. This provides a relatively straightforward route for realizing traps with an electrode structure on the 100 micron scale with high optical access. We demonstrate the basic functionality of the trap by cooling a single ion to the quantum ground state, allowing us to measure a heating rate from the ground state of 787 +/- 24 quanta/s. Variation of the fabrication procedure used here may provide access to traps in this geometry with trap scales between 100 mu m and 10 mu m. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.
Raman amplification of pure side-seeded higherorder modes in
hydrogen-filled hollow-core PCF
Jean-Michel Menard,
Barbara M. Trabold,
Amir Abdolvand,
Philip St J. Russell
We use Raman amplification in hydrogen-filled hollow-core kagome photonic crystal fiber to generate high energy pulses in pure single higher-order modes. The desired higher-order mode at the Stokes frequency is precisely seeded by injecting a pulse of light from the side, using a prism to select the required modal propagation constant. An intense pump pulse in the fundamental mode transfers its energy to the Stokes seed pulse with measured gains exceeding 60 dB and output pulse energies as high as 8 mu J. A pressure gradient is used to suppress stimulated Raman scattering into the fundamental mode at the Stokes frequency. The growth of the Stokes pulse energy is experimentally and theoretically investigated for six different higher-order modes. The technique has significant advantages over the use of spatial light modulators to synthesize higher-order mode patterns, since it is very difficult to perfectly match the actual eigenmode of the fiber core, especially for higher-order modes with complex multi-lobed transverse field profiles. (C) 2015 Optical Society of America
Engineering of a Ge-Te-Se glass fibre evanescent wave spectroscopic (FEWS) mid-IR chemical sensor for the analysis of food and pharmaceutical products
Xin Jiang,
Animesh Jha
SENSORS AND ACTUATORS B-CHEMICAL
206
159-169
(2015)
| Journal
Using an unclad multimode Ge-Te-Se based chalcogenide glass fibre, simple design robust fibre evanescent wave spectroscopic (FEWS) sensor is demonstrated. Methodologies adopted for material development and fibre drawing are discussed in the following steps: purification of raw materials for high spectral purity, fabrication of glass and fibre preform leading to fibre drawing. The fabricated fibre has a minimum loss of 1.4 dB/m at 4.2 mu m, and less than 3 dB/m between 1.5 and 6.3 mu m. The feasibility of using such a fibre for evanescent wave spectroscopic sensing has been verified by using the finite-element (FE) computation technique. Supported optical modes as well as corresponding penetration depths of evanescent fields from different modes are discussed. Based on the FE computation, a FEWS sensor consisting of a 40 cm Ge-Te-Se fibre, coupled with a Fourier transform infrared (FTIR) spectrometer and a liquid nitrogen cooled mercury-cadmium-tellurium (MCT) detector, is demonstrated. The active length along this fibre employed for sensing is 3 cm. Based on FEWS design, the fabricated fibre sensor was used for the analysis of chemicals, namely the acetone, ethanol, methanol, tocopherol (vitamin E), ascorbic acid (vitamin C), fresh orange and lemon juice. (C) 2014 Elsevier B.V. All rights reserved.
Stable subpicosecond soliton fiber laser passively mode-locked by gigahertz acoustic resonance in photonic crystal fiber core
M. Pang,
X. Jiang,
W. He,
G. K. L. Wong,
G. Onishchukov,
N. Y. Joly,
G. Ahmed,
C. R. Menyuk,
P. St J. Russell
Ultrafast lasers with high repetition rates are of considerable interest in applications such as optical fiber telecommunications, frequency metrology, high-speed optical sampling, and arbitrary waveform generation. For fiber lasers mode-locked at the cavity round-trip frequency, the pulse repetition rate is limited to tens or hundreds of megahertz by the meter-order cavity lengths. Here we report a soliton fiber laser passively mode-locked at a high harmonic (similar to 2 GHz) of its fundamental frequency by means of optoacoustic interactions in the small solid glass core of a short length ( 60 cm) of photonic crystal fiber. Due to tight confinement of both light and vibrations, the optomechanical interaction is strongly enhanced. The long-lived acoustic vibration provides strong modulation of the refractive index in the photonic crystal fiber core, fixing the soliton spacing in the laser cavity and allowing stable mode-locking, with low pulse timing jitter, at gigahertz repetition rates. (C) 2015 Optical Society of America
Raman-induced temporal condensed matter physics in gas-filled photonic
crystal fibers
Mohammed F. Saleh,
Andrea Armaroli,
Truong X. Tran,
Andrea Marini,
Federico Belli,
Amir Abdolvand,
Fabio Biancalana
Raman effect in gases can generate an extremely long-living wave of coherence that can lead to the establishment of an almost perfect temporal periodic variation of the medium refractive index. We show theoretically and numerically that the equations, regulate the pulse propagation in hollow-core photonic crystal fibers filled by Raman-active gas, are exactly identical to a classical problem in quantum condensed matter physics - but with the role of space and time reversed - namely an electron in a periodic potential subject to a constant electric field. We are therefore able to infer the existence of Wannier-Stark ladders, Bloch oscillations, and Zener tunneling, phenomena that are normally associated with condensed matter physics, using purely optical means. (C) 2015 Optical Society of America
Recent Advances in Theory and Applications of Electromagnetic
Metamaterials
Weiren Zhu,
Ivan D. Rukhlenko,
Roman E. Noskov,
Ronghong Jin,
Ji Zhou
INTERNATIONAL JOURNAL OF ANTENNAS AND PROPAGATION
982325
(2015)
| Journal
Dramatic Raman Gain Suppression in the Vicinity of the Zero Dispersion
Point in a Gas-Filled Hollow-Core Photonic Crystal Fiber
In 1964 Bloembergen and Shen predicted that Raman gain could be suppressed if the rates of phonon creation and annihilation (by inelastic scattering) exactly balance. This is only possible if the momentum required for each process is identical, i.e., phonon coherence waves created by pump-to-Stokes scattering are identical to those annihilated in pump-to-anti-Stokes scattering. In bulk gas cells, this can only be achieved over limited interaction lengths at an oblique angle to the pump axis. Here we report a simple system that provides dramatic Raman gain suppression over long collinear path lengths in hydrogen. It consists of a gas-filled hollow-core photonic crystal fiber whose zero dispersion point is pressure adjusted to lie close to the pump laser wavelength. At a certain precise pressure, stimulated generation of Stokes light in the fundamental mode is completely suppressed, allowing other much weaker phenomena such as spontaneous Raman scattering to be explored at high pump powers.
Wideband-tunable soliton fiber laser mode-locked at 1.88 GHz by
optoacoustic interactions in solid-core PCF
We report a wavelength-tunable soliton fiber laser stably mode-locked at 1.88 GHz (the 389th harmonic of the cavity round-trip frequency) by a light-driven acoustic resonance in the core of a photonic crystal fiber. Stable high-harmonic mode-locking could be maintained when the lasing wavelength was continuously tuned from 1532 to 1566 nm by means of an optical filter placed inside the laser cavity. We report on the experimental performance of the laser, including its power scalability, super-mode noise suppression ratio, long-term repetition rate stability, short-term pulse amplitude noise and timing jitter, optical comb structure and pulse-to-pulse phase fluctuations. (C) 2015 Optical Society of America
Kontakt
Bitte richten Sie forschungsbezogene Anfragen an philip.russell@mpl.mpg.de und allgemeine Anfragen an Bettina Schwender:
Max-Planck-Institut für die Physik des Lichts Staudtstr. 2 91058 Erlangen
