Bragg reflective polychromatic vector beam generation from opposite-handed cholesteric liquid crystals
In this Letter, a method of stacking two opposite-handed cholesteric liquid crystals (CLCs) with the same pitches and the same surface azimuthal angles to generate vector beams from homogeneous linear polarization is proposed. By this means, vector beams with arbitrary orders can be generated based ... (Source: Optics Letters)
Source: Optics Letters - May 22, 2019 Category: Physics Authors: Tiegang Lin Yide Yuan Yaqin Zhou Wenxing Fu Huihui Huang Lishuang Yao Fan Fan Shuangchun Wen Source Type: research

Motion-based coherent optical imaging in heavily scattering random media
We present a simple imaging method involving the correlation of speckle patterns as a function of ... (Source: Optics Letters)
Source: Optics Letters - May 22, 2019 Category: Physics Authors: Qiaoen Luo Jason A. Newman Kevin J. Webb Source Type: research

Megawatt solitons generated above 2000     nm in Bragg fibers
Solitonic effects, including multi-solitonic fission and subsequent self-frequency shift, are used to tailor ultrashort (sub-100   fs) pulses with carrier wavelength broadly tunable in spectral regions between fixed laser lines. Although high-energy pulses can be obtained in stiff waveguides, ... (Source: Optics Letters)
Source: Optics Letters - May 22, 2019 Category: Physics Authors: H. Delahaye G. Granger D. Gaponov L. Lavoute S. Aleshkina M. Salganskii A. Hideur M. Likhachev S. F é vrier Source Type: research

Simple phase noise measurement scheme for cavity-stabilized laser systems
We describe a simple method for measuring the residual fast phase noise of a cavity-stabilized laser using the cavity as a reference. The method is based on generating a beat note between the laser output and the strongly filtered light transmitted through the cavity. The beat note can be directly ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Fabian Schmid Johannes Weitenberg Theodor W. H ä nsch Thomas Udem Akira Ozawa Source Type: research

Eigenmode hybridization enables lattice-induced transparency in symmetric terahertz metasurfaces for slow light applications
Traditional lattice-induced transparency demonstrations are activated by varying the meta-atom lattice constant such that the plasmonic and lattice modes interfere. Here we report on the observation of enhanced coupling between two eigenmodes (first- and second-order) by varying the lattice ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Joshua A. Burrow Riad Yahiaoui Andrew Sarangan Jay Mathews Imad Agha Thomas A. Searles Source Type: research

Investigation on the optical properties of annealed Mn-Co-Ni-O thin films by spectroscopic ellipsometry
Mn-Co-Ni-O thin films have been widely used for their excellent negative temperature coefficient features, but investigations about tailoring their structural and optical properties via a post-annealing (PA) process are still rare in recent years. In this Letter, we derived the visible to ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Wei Zhou Yi Liu Yimin Yin Wanli Ma Zhiming Huang Source Type: research

Point-dipole model for metal-enhanced fluorescence
A simple analytical model for calculating the Purcell factor in metal-enhanced fluorescence (MEF) may replace its difficult precise calculations involving either the Green function of a plasmonic nanoantenna (NA) or the resonator mode volume. The model considers the NA as a point dipole. It was ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Constantin R. Simovski Source Type: research

Fiber Bragg grating with a waveguide fabricated in no-core fiber and multimode fiber
A new, to the best of our knowledge, method of fabricating a fiber Bragg grating (FBG) in no-core fiber (NCF) and multimode fiber (MMF) is proposed and demonstrated, achieved by writing an in-fiber waveguide before the grating inscription. This approach makes it possible to fabricate the FBG in NCF ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Qiaohan Wang D. N. Wang Hua Zhang Source Type: research

Orbital angular momentum demultiplexing with synthetic partial aperture receivers
Long-distance transmitted orbital angular momentum (OAM) cannot be received completely by a single aperture receiver due to the divergence of OAM beams in free space, which results in a challenge for measuring and demultiplexing the multi-OAM modes. We propose a novel approach in measuring ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Duo Deng Yan Li Hua Zhao Yi Liu Shiliang Qu Source Type: research

Near diffraction-limited laser output from a very large size rectangular core crystalline waveguide
laser was achieved experimentally. A crystalline waveguide, with a rectangular core size of 320     μ m × 400     μ m by 1.0   at.% Yb:YAG (core) and ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Xing Hu Dejiang Cheng Hong Lei Yongling Hui Menghua Jiang Qiang Li Source Type: research

Shape-adapting panoramic photoacoustic endomicroscopy
Photoacoustic (PA) endoscopy (PAE) has exhibited potential for providing the complementary contrast to available optical endoscopy methods, particularly for deep vessel imaging. In this Letter, a prototype PA endoscope with shape imaging was developed for the first time, to the best of our ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Kedi Xiong Wei Wang Ting Guo Zhen Yuan Sihua Yang Source Type: research

Noise reduction in resonator-based ultrasound sensors by using a CW laser and phase detection
The detection of ultrasound via optical resonators is conventionally performed by tuning a continuous-wave (CW) laser to the linear slope of the resonance and monitoring the intensity modulation at the resonator output. While intensity monitoring offers the advantage of simplicity, its sensitivity ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Lucas Riob ó Yoav Hazan Francisco Veiras Mar í a Garea Patricio Sorichetti Amir Rosenthal Source Type: research

30     GHz electro-optic frequency comb spanning 300     THz in the near infrared and visible
Beginning with a continuous wave laser at 1064   nm, we generate a 30   GHz electro-optic frequency comb which contains 100 lines spanning 3   THz. The initial comb is subsequently amplified, spectrally broadened in normal dispersion photonic crystal fiber, and then temporally ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: Andrew J. Metcalf Connor D. Fredrick Ryan C. Terrien Scott B. Papp Scott A. Diddams Source Type: research

Optical fiber lasers assisted by microdrilled optical fiber tapers
In this Letter, we present an analysis of the backscattering generated in a microdrilled tapered fiber within a short-linear-cavity fiber laser. We propose and experimentally demonstrate a fiber cavity laser based on a tapered optical fiber segment that generates artificially controlled ... (Source: Optics Letters)
Source: Optics Letters - May 21, 2019 Category: Physics Authors: R. A. Perez-Herrera D. Pallar é s-Aldeiturriaga A. J ú dez L. Rodriguez Cobo M. Lopez-Amo J. M. Lopez-Higuera Source Type: research

Noise-reduced optical ultrasound sensor via signal duplication for photoacoustic microscopy
Fiber-laser-based ultrasound sensors have attracted great interest because of their applications in compact and endoscopic imaging modalities. The noises of such an ultrasound sensor may originate from its light source, optical amplifier, photodetector, and data acquisition card. Here we present an ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: Yizhi Liang Jin-Wei Liu Lidai Wang Long Jin Bai-Ou Guan Source Type: research

One-dimensional solitons in fractional Schr ö dinger equation with a spatially periodical modulated nonlinearity: nonlinear lattice
The existence and stability of stable bright solitons in one-dimensional (1D) fractional media with a spatially periodical modulated Kerr nonlinearity (nonlinear lattice), supported by the recently introduced nonlinear fractional Schr ö dinger equation, are demonstrated by means of the ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: Liangwei Zeng Jianhua Zeng Source Type: research

Dissipative dispersion-managed solitons in fiber-optic systems with lumped amplification
We numerically and experimentally studied the shape of the dissipative dispersion-managed solitons (DM-solitons) stably propagating over the lossy DM fiber-optic systems with lumped amplification. We found that, contrary to the lossless case, the chirp-free points of the dissipative DM-solitons are ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: Vladislav Neskorniuk Anton Lukashchuk George Ovchinnikov Franko K ü ppers Arkadi Chipouline Source Type: research

Drop-in two-dimensional electronic spectroscopy based on dual modulation in the pump-probe geometry
We report a compact design of two-dimensional electronic spectrometer (2DES) which can be built from any femtosecond broadband transient absorption setup using only a few optical elements and dual beam modulation by a single chopper blade. The dual pulse modulation design provides automatic ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: Daniel G. Oblinsky Evgeny E. Ostroumov Gregory D. Scholes Source Type: research

Laser wave-packet representation to unify eigenmodes and geometric modes in spherical cavities
In terms of the Gaussian beam parameter and Gouy phase, the parametric equations for geometric rays of periodic orbits in spherical resonators are originally generalized as the real parts of polar forms. The derived polar forms are employed to create an analytical wave-packet representation for ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: Y. F. Chen S. C. Li Y. H. Hsieh J. C. Tung H. C. Liang K. F. Huang Source Type: research

Classical entanglement underpins the invariant propagation of space – time wave packets
Propagation-invariant pulsed beams are generated by introducing appropriate tight correlations in their spatiotemporal spectrum. Such correlations constitute an example of what has been called “ classical entanglement, ” which is a necessary but insufficient requirement for propagation ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: H. Esat Kondakci Miguel A. Alonso Ayman F. Abouraddy Source Type: research

Symmetry breaking with opposite stability between bifurcated asymmetric solitons in parity-time-symmetric potentials
We report a new type of symmetry-breaking bifurcation of solitons in optical systems with parity-time-symmetric potentials. In this bifurcation, the two bifurcated branches of asymmetric solitons exhibit opposite stability, which contrasts all previous symmetry-breaking bifurcations in conservative ... (Source: Optics Letters)
Source: Optics Letters - May 16, 2019 Category: Physics Authors: Jianke Yang Source Type: research

Spatio-temporal enhancement of Raman-induced frequency shifts in graded-index multimode fibers
We investigate the impact of intrapulse Raman scattering and third-order dispersion on the propagation of a pulsed optical beam inside graded-index (GRIN) fibers by solving an effective nonlinear Schr ö dinger equation that includes the spatial self-imaging effects through a periodically ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Amira S. Ahsan Govind P. Agrawal Source Type: research

Structure-resolving index: an efficient criterion for ending image acquisition in super-resolution localization microscopy
In super-resolution localization microscopy, a final super-resolution image is built upon a huge amount of raw image frames (typically>10,000). To guarantee the quality of a final super-resolution image, researchers tend to collect as many raw images as possible, leading to excess data volume, ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Yujie Wang Bo Xin Zhen-Li Huang Source Type: research

Low-loss broadband 5     ×     5 non-blocking Si_3N_4 optical switch matrix
An integrated 5 × 5 non-blocking optical switch matrix is proposed and experimentally demonstrated based on the silicon nitride (Si_3N_4) platform. The proposed optical switch matrix is designed with the Spanke – Benes architecture having 10 balanced Mach – Zehnder interferometers, ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Di Zheng Jos é David Dom é nech Wei Pan Xihua Zou Lianshan Yan Daniel P é rez Source Type: research

Scalable and efficient source of entangled frequency bins
We present a scalable and efficient approach for the generation of frequency-bin encoded qudit states in photonic integrated devices. We exploit a series of coherently pumped resonators, each generating photon pairs in specific frequency bins via spontaneous four-wave mixing. The generated state ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Marco Liscidini J. E. Sipe Source Type: research

Propagation of partially coherent truncated polymorphic beams
The recently introduced concept of coherent polymorphic beam (PB), which is focused into a 2D light curve of arbitrary form with independently prescribed phase along it, is a fruitful generalization of the “ perfect ” ring vortex and opens up new perspectives in all-optical particle ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Mercedes Angulo Jos é A. Rodrigo Tatiana Alieva Source Type: research

Photonic “ hourglass ” design for efficient quantum light emission
We propose a novel “ hourglass ” -shaped design for highly efficient generation and collection of quantum light. The design features a quantum dot in a photonic nanowire sandwiched between tapered Bragg reflectors. For a Purcell factor of 9, the design features a spontaneous emission ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Andreas Dyhl Osterkryger Julien Claudon Jean-Michel G é rard Niels Gregersen Source Type: research

Quasi-kilowatt random fiber laser
The random distributed-feedback Raman fiber laser (RRFL) is a new approach to obtain a high-power laser. In this Letter, we report a RRFL with quasi-kilowatt output power for the first time based on a half-open cavity. It consists of a piece of a large-mode-area passive fiber with a core diameter ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Hanwei Zhang Long Huang Jiaxin Song Han Wu Pu Zhou Xiaolin Wang Jian Wu Jiangming Xu Zinan Wang Xiaojun Xu Yunjiang Rao Source Type: research

Refractive-index-based ultrasound sensing with photonic crystal slabs
We demonstrate ultrasound detection with 500- μ m-diameter photonic-crystal slab (PCS) sensors fabricated from CMOS-compatible technology. An ultrasound signal impinging a PCS sensor causes a local modulation of the refractive index (RI) of the medium (water) in which the PCS is immersed, ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Eric Y. Zhu Cory Rewcastle Raanan Gad Li Qian Ofer Levi Source Type: research

Semiconductor-laser-based hybrid chaos source and its application in secure key distribution
An analog – digital hybrid optical chaos source and a corresponding secure key distribution (SKD) scheme are proposed. An analog – digital hybrid electro-optic feedback loop is introduced to enhance the robustness of the chaotic semiconductor lasers. The source, which can adopt robust ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Zexi Zhao Mengfan Cheng Chenkun Luo Lei Deng Minming Zhang Songnian Fu Ming Tang Ping Shum Deming Liu Source Type: research

Improving sub-pixel shifts estimation in a Shack – Hartmann wavefront sensor
In the paper, we propose a simple algorithm that improves the quality with which the displacements between images registered in the sub-apertures of a a Shack – Hartmann (SH) wavefront sensor can be determined. Instead of measuring shifts between a given sub-aperture and a reference image, the ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Popowicz Adam Source Type: research

Low dark current and high-responsivity graphene mid-infrared photodetectors using amplification of injected photo-carriers by photo-gating
Low dark current, high-responsivity middle-wavelength infrared (IR) graphene photodetectors using photo-gating amplification of injected photo-carriers are demonstrated. A graphene/p-indium antimonide (InSb) heterojunction and graphene/insulator region were formed. The injected photo-carriers from ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Shoichiro Fukushima Masaaki Shimatani Satoshi Okuda Shinpei Ogawa Yasushi Kanai Takao Ono Koichi Inoue Kazuhiko Matsumoto Source Type: research

Nanosecond laser coupling for increased filament ablation
Laser filaments can project intensities sufficient to ablate materials at long ranges, but the clamping of a filament ’ s intensity to ∼ 10^14     W/cm^2 limits the effective ablation of targets with which the laser pulses interact. We seek to identify regimes in which ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Haley Kerrigan Shermineh Rostami Fairchild Martin Richardson Source Type: research

Noncontact photoacoustic imaging based on optical quadrature detection with a multiport interferometer
A noncontact photoacoustic imaging method based on optical quadrature detection is proposed. The photo-induced acoustic signal is detected by an optical method without contacting the specimen. By utilizing the intrinsic phase difference of a multiport optical interferometer, the quadrature signal ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Soongho Park Sunghwan Rim Younggue Kim Byeong Ha Lee Source Type: research

Experimental demonstration of a graphene-based hybrid plasmonic modulator
In this Letter, we report a graphene-based hybrid plasmonic modulator (GHPM) realized by employing the electro-absorption effect of graphene. The simulation results show that the modulation efficiency of GHPM, i.e., extinction ratio per length, can be as large as 0.417   dB/ μ m, which is ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Ran Hao Jianyao Jiao Xiliang Peng Zheng Zhen Rakhatbek Dagarbek Yijun Zou Erping Li Source Type: research

Compact hard x-ray split-delay system based on variable-gap channel-cut crystals
We present the concept and a prototypical implementation of a compact x-ray split-delay system that is capable of performing continuous on-the-fly delay scans over a range of ∼ 10     ps with sub-100 nanoradian pointing stability. The system consists of four channel-cut silicon ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Yanwen Sun Nan Wang Sanghoon Song Peihao Sun Matthieu Chollet Takahiro Sato Tim B. van Driel Silke Nelson Rajan Plumley Jordi Montana-Lopez Samuel W. Teitelbaum Johann Haber Jerome B. Hastings Alfred Q. R. Baron Mark Sutton Paul H. Fuoss Aymeric Robert Di Source Type: research

Constant temperature operation of fiber-optic hot-wire anemometers
We demonstrate the constant temperature (CT) operation of a fiber-optic anemometer based on a laser-heated silicon Fabry – Perot interferometer (FPI), where the temperature of the FPI is kept constant by adjusting the heating laser power through a feedback control loop and the output signal is ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Nezam Uddin Guigen Liu Qiwen Sheng Ming Han Source Type: research

Contactless online characterization of large-area conductive thin films by thermography and induction
Testing and characterization techniques intended for traditional electronics production are rarely compatible with modern large-area, thin film electronics manufacturing processes such as roll-to-roll fabrication. Online quality monitoring of conductive thin films is necessary for upscaling and ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Kari Remes Antti J ä rvenp ä ä Tapio Fabritius Source Type: research

Picosecond laser welding of glasses with a large gap by a rapid oscillating scan
A welding method that utilizes a picosecond laser with a small-scale rapid oscillating scan is presented in this Letter to achieve the welding of glasses with natural stacking contact (gap ≈ 10     μ m). The rapid oscillating scan of the laser not only creates enough molten ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Hang Chen Leimin Deng Jun Duan Xiaoyan Zeng Source Type: research

Broadband mid-infrared coverage (2 – 17     μ m) with few-cycle pulses via cascaded parametric processes
A myriad of existing and emerging applications could benefit from coherent and broadband mid-infrared (MIR) light. Yet, existing tabletop sources are often complex or sensitive to interferometric optical misalignment. Here we demonstrate a significantly simplified scheme of broadband MIR generation ... (Source: Optics Letters)
Source: Optics Letters - May 15, 2019 Category: Physics Authors: Qing Wang Jinwei Zhang Alexander Kessel Nathalie Nagl Vladimir Pervak Oleg Pronin Ka Fai Mak Source Type: research

Set of 4d – 3 observables to determine any pure qudit state
We present a tomographic method which requires only 4d − 3 measurement outcomes to reconstruct any pure quantum state of arbitrary dimension d. Using the proposed scheme, we have experimentally reconstructed a large number of pure states of dimension d=7, obtaining a mean fidelity of 0.94. ... (Source: Optics Letters)
Source: Optics Letters - May 10, 2019 Category: Physics Authors: Quimey Pears Stefano Lorena Reb ó n Silvia Ledesma Claudio Iemmi Source Type: research

Method to reduce the aberration of a polygonal aperture focus-tunable lens array for high fill factor
Focus-tunable liquid lens arrays have been used to improve depth in glass-free three-dimensional devices where high fill factor is required. For high fill factors, polygonal apertures should be used, but due to the difficulty of controlling aberrations during focus tuning, polygonal aperture ... (Source: Optics Letters)
Source: Optics Letters - May 10, 2019 Category: Physics Authors: Junoh Kim Jooho Lee Yong Hyub Won Source Type: research

3.5-mJ 150-fs Fe:ZnSe hybrid mid-IR femtosecond laser at 4.4     μ m for driving extreme nonlinear optics
We report on entering a new era of mid-IR femtosecond lasers based on amplification in a relatively new gain chalcogenide medium, Fe:ZnSe. Our hybrid all-solid-state laser system is based on direct pulse amplification of femtosecond seed from three-stage AGS-based-optical parametric amplification ... (Source: Optics Letters)
Source: Optics Letters - May 10, 2019 Category: Physics Authors: Ekaterina Migal Andrey Pushkin Boris Bravy Vyacheslav Gordienko Nikita Minaev Anatoly Sirotkin Fedor Potemkin Source Type: research

Optically tunable fiber Bragg grating based on a photo-mechanical tuning mechanism
We present an optically tunable fiber Bragg grating (FBG) based on a photo-mechanical tuning mechanism. Azobenzene containing polymer was utilized as a photo-mechanical tuning agent coated over a bare section of FBG. Controlled by ultraviolet (UV) irradiation, the polymer coating acts as a ... (Source: Optics Letters)
Source: Optics Letters - May 10, 2019 Category: Physics Authors: Tae-Jung Ahn Sucbei Moon Source Type: research

Quartz tuning fork embedded off-beam quartz-enhanced photoacoustic spectroscopy
In order to achieve a high acoustic coupling strength and detection sensitivity and to simplify the assembly and alignment process in quartz-enhanced photoacoustic spectroscopy (QEPAS) technique, a novel quartz tuning fork (QTF) embedded off-beam QEPAS (E-OB-QEPAS) spectrophone was proposed. The ... (Source: Optics Letters)
Source: Optics Letters - May 10, 2019 Category: Physics Authors: Lien Hu Chuantao Zheng Jie Zheng Yiding Wang Frank K. Tittel Source Type: research

Femtosecond two-photon absorption phase change spectroscopy of a ZnSe single crystal
We measured time- and frequency-resolved phase changes owing to two-photon absorption induced by ultrashort (10   fs) pulses transmitted through a transparent material (ZnSe crystal), using femtosecond two-photon phase change spectroscopy. The maximal phase change was 0.02   rad when a ... (Source: Optics Letters)
Source: Optics Letters - May 9, 2019 Category: Physics Authors: Khos-Ochir Tsogvoo Baatarchuluun Tsermaa Byung Kwan Yang Kim Myung-Whun Source Type: research

Effects of orbital angular momentum on few-cycle and sub-cycle pulse shapes: coupling between the temporal and angular momentum degrees of freedom
We describe the effects of the coupling between the orbital angular momentum (OAM) and the temporal degrees of freedom in pulsed Laguerre – Gauss beams as a significant increase of the duration of few-cycle pulses when the OAM carried by the pulse is large, and as an enhancement to other ... (Source: Optics Letters)
Source: Optics Letters - May 9, 2019 Category: Physics Authors: Miguel A. Porras Source Type: research

Grating-like nanostructures formed by the focused fs laser pulse in the volume of transparent dielectric
The evolution of optical discharge induced in the volume of transparent dielectric by a focused fs laser pulse is studied under condition of ionization instability that results in deep small-scale periodic modulation of breakdown plasma parameters in the direction of laser polarization. Laser pulse ... (Source: Optics Letters)
Source: Optics Letters - May 9, 2019 Category: Physics Authors: V. B. Gildenburg I. A. Pavlichenko Source Type: research

Probing topological phases in waveguide superlattices
One-dimensional superlattices with modulated coupling constants show rich topological properties and tunable edge states. Beyond the dimeric case, probing the topological properties of superlattices is a challenge. Here we suggest a rather general method of bulk probing topological invariants in ... (Source: Optics Letters)
Source: Optics Letters - May 9, 2019 Category: Physics Authors: Stefano Longhi Source Type: research

Noninvasive three-dimensional imaging through scattering media by three-dimensional speckle correlation
We present a method for noninvasive three-dimensional imaging through scattering media by using a three-dimensional memory effect in scattering phenomena. In the proposed method, an object in a scattering medium is reconstructed from a three-dimensional autocorrelation of speckle images captured by ... (Source: Optics Letters)
Source: Optics Letters - May 9, 2019 Category: Physics Authors: Yuka Okamoto Ryoichi Horisaki Jun Tanida Source Type: research