bluuebunny/crossref_metadata_2025 huggingface dataset:
Versatile Spectral Shaping of Spectrally Incoherent Pulses in the IR and UV
Authors: Spilatro M. , Dorrer C.
Published: January 2022

We demonstrate the generation of spectrally incoherent pulses with
controlled spectral properties using a fiber front end and an optical
parametric amplifier for application to the mitigation of laser–plasma
instabilities in high-energy laser-plasma experiments.
Power Scaling and Thermal Lensing in ~2.8 μm Er:CaF2 Lasers: Effect of the Pump Wavelength
Authors: Basyrova Liza , Loiko Pavel , Doualan Jean-Louis , Benayad Abdelmjid , Braud Alain , Viana Bruno , Camy Patrice
Published: January 2022

Er:CaF2 laser generated 0.83 W at 2800 nm with a slope
efficiency of 31.6% and a threshold of 24 mW. Thermal lensing and heat
loading are compared under pumping into the
4I11/2 and 4I9/2
states.
Solid-State Laser Technology for Frequency-Comb Spectroscopy
Authors: Picqué Nathalie
Published: January 2022

Advanced solid-state laser instrumentation advances the frontiers of
frequency comb techniques, including dual-comb spectroscopy.
Integrated photonics holds much promise for a gas-phase dual-comb
spectrometer on a photonic chip.
Comparison of Spectroscopic and Laser Properties of Cr2+,Fe2+:Zn1-xMnxSe (x ≈ 0.2 and x ≈ 0.4) Single Crystals under Er:YLF Laser Excitation at ~1.73 µm
Authors: Říha Adam , Jelínková Helena , Doroshenko Maxim E. , Jelínek Michal , Šulc Jan , Němec Michal , Čech Miroslav , Kovalenko Nazar O.
Published: January 2022

We report the Cr2+ → Fe2+ ions energy transfer
under ~1.73 µm excitation of the
Cr2+,Fe2+:Zn1-xMnxSe (x ≈
0.2) single crystal for the first time and the results were compared
with the crystal containing ~2× higher manganese amount (x ≈ 0.4) in
the host material. Mid-infrared laser generation from Cr2+
ions at ~2.3 µm and ~2.5 µm, and from Fe2+ ions at ~4.4 µm
and ~4.75 µm of the x ≈ 0.2 and x ≈ 0.4 samples, respectively, is
presented.
Long wavelength multi-watt dysprosium fiber laser for resonant polymer ablation
Authors: Pleau Louis-Philippe , Fortin Vincent , Boilard Tommy , Jobin Frédéric , Vallée Réal , Messaddeq Younès , Bernier Martin
Published: January 2022

We demonstrate a dysprosium fiber laser emitting 3 W of continuous,
single-mode power at a wavelength of 3.42 µm, the longest wavelength
for a multi-watt Dysprosium fiber laser, corresponding with an
absorption band of polyethylene.
Towards Multi-Milijoule Short-Pulse Mid-Infrared Fluoride Fiber Amplifiers
Authors: Aydın Yiğit Ozan , Magnan-Saucier Sébastien , Zhang Daiying , Fortin Vincent , Kraemer Darren , Vallée Réal , Bernier Martin
Published: January 2022

We report 1 mJ energy, sub-ns pulses at 5 W average power near 3 µm
from an erbium-doped fluoride fiber amplifier.
Low-Water-Peak Bismuth-Doped Fiber for Efficient O+E Band Amplifiers
Authors: Ososkov Yan , Khegai Aleksandr , Firstov Sergei , Riumkin Konstantin , Alyshev Sergey , Kharakhordin Alexander , Guryanov Alexey , Lobanov Alexey , Melkumov Mikhail
Published: January 2022

In this paper, we demonstrate a bismuth-doped active fiber suitable for
the development of fiber lasers and broadband amplifiers in the 1.3 –
1.46 µm spectral region. Here we point to the fiber features that
determine its overall efficiency as well as discuss measurement
results.
Fabrication of Yb:YAG-derived silica fiber from powder-in-tube method and its application in single-frequency fiber laser
Authors: Qi Fuxin , Zheng Baoluo , Yang Jing , Li Biao , Liu Jinming , Zhang Xin , Zhang Qian , Hou Yubin , Wang Pu
Published: January 2022

A Yb:YAG-derived silica fiber with a doping concentration of 3.75 wt%
for Yb2O3 was fabricated by powder-in-tube
method. A single-frequency fiber laser was constructed using the fiber
length of 1cm with 28dB-absorption at 976nm.
Tm:Y2O3 ceramic laser in-band pumped at 1620 nm
Authors: Huang Weiwei , Wang Fei , Wang Jun , Shen Deyuan , Tang Dingyuan
Published: January 2022

We report on a Tm:Y2O3 ceramic laser in-band
pumped at 1620 nm using homemade sample, generating 5.5 W of CW power
at 2050 nm with slope efficiency of 53% with respect to incident pump
power.
2µm pulse compression in a hollow-core fiber at a 1 kHz repetition rate – 86 fs pulses with 0.2 TW peak power
Authors: Nagy Tamas , von Grafenstein Lorenz , Ueberschaer Dennis , Griebner Uwe
Published: January 2022

Hollow-core fiber-based post-compression of 45 mJ few-ps pulses at 2.05
µm is reported. Pulses as short as 86 fs with 20.8 mJ energy are
achieved at a 1 kHz repetition rate.
All-Fiber Mid-IR OPCPA Front-End and Cryogenic Yb:YAG Pump Laser for Soft X-ray Generation
Authors: Morrill D. , Carlson D. , Lesko D. , Wu T.-H. , Diddams S. , Murnane M. , Kapteyn H. , Hemmer M.
Published: January 2022

We report a mid-IR OPCPA all-fiber front-end and cryogenic Yb:YAG pump
laser. The front-end delivers pulses at 1.5-μm and 1-μm. The Yb:YAG
amplifier boosts these pulses to 5-mJ, 1-kHz. The systems operate
uninterrupted for weeks.
Intra-Cavity Spin-Orbit Angular Momentum Conversion with a Sagnac Interferometer Laser
Authors: Kerridge-Johns William R.
Published: January 2022

We propose and experimentally demonstrate a new method for laser
intra-cavity spin-orbit conversion with a q-plate. The
Nd:YVO4 laser yielded a high quality LG01
output. We observed a self-adapting resonator that minimized
high-order radial modes.
743 nm Source by SHG of a Cascaded Phosphosilicate Raman Fiber Amplifier
Authors: Chandran A. M. , Battle R. A. , Murray R. T. , Runcorn T. H. , Taylor J. R.
Published: January 2022

We demonstrate a nanosecond-pulsed 743 nm source by second harmonic
generation of a cascaded phosphosilicate Raman fiber amplifier
operating at 1485 nm. The source emits >1 W of 743
nm average power at a 5 MHz repetition rate.
Performances of mid-IR high-power ZGP OPOs compared in non-planar ring resonators
Authors: Medina M. A. , Piotrowski M. , Schellhorn M. , Wagner F. R. , Berrou A. , Hildenbrand-Dhollande A.
Published: January 2022

We compared the performances of two mid-infrared non-planar ring ZGP
OPO resonators, generating up to 30 W (RISTRA) and 27 W (FIRE). The
beam quality is significantly improved from a value of M2
< 1.8 (RISTRA) to M2 < 1.4 (FIRE).
Lasing performance of crystalline-coated Yb:YAG thin disks
Authors: Cimrman Martin , Cvrček Jan , Foršt Ondřej , Smrž Martin , Novák Ondřej , Jelínek Michal , Chyla Michal , Mocek Tomáš
Published: January 2022

Efficient heat management of Yb:YAG thin disk based on new highly
thermally conductive crystalline coating is proved by thermal and
lasing characteristics when it is used in a simple, multi-mode laser
cavity under 940-nm pumping.
Operation of the Gain-Switched Laser in the Self-Injection Locking Regime to a Microcavity
Authors: Shitikov Artem E. , Kondratiev Nikita M. , Lobanov Valery E. , Lonshakov Evgeny A. , Bilenko Igor A.
Published: January 2022

We experimentally demonstrated a self-injection locking of a laser
diode in gain-switched regime to a high-quality-factor microresonator.
The frequency combs with continuously tunable line-spacing and narrow
teeth linewidths were observed.
Spectral broadening in a hollow core capillary and post compression of millijoule picosecond pulses at 2 μm
Authors: Flöry T. , Astrauskas I. , Carpeggiani P. , Baltuška A. , Pugžlys A.
Published: January 2022

We present results from spectral broadening of 4.6 mJ picosecond-pulses
from a Ho:YAG regenerative amplifier at 2.09 μm in a hollow core
capillary. The spectrally broadened pulses are recompressed using a
reflective grating compressor.
CALIPR: Coherent Addition using Learned Interference Pattern Recognition
Authors: Wang Dan , Du Qiang , Zhou Tong , Bakalis Christos , Li Derun , Wilcox Russell
Published: January 2022

We use machine learning to recognize interference patterns from
diffractive coherent beam combinations, to derive a phase error signal
for feedback. The scheme is shown in the simulation to be robust
against drift during training.
Stabilizing Coherently Combined Beam Power using a Robust Learning Algorithm
Authors: Du Qiang , Wang Dan , Zhou Tong , Bakalis Christos , Vytla Vamsi , Li Derun , Wilcox Russell
Published: January 2022

A machine-learning phase stabilizer for 8-beam diffractive coherent
combination controls output power to < 0.4% RMS,
using interference pattern recognition. The learning neural network is
trained while combiner phases drift, using a two-state dither
scheme.
2 kW fiber laser based on 20 µm-core double-cladding fibers and 915 nm pump sources
Authors: Lin Weixuan , Desjardins-Carrière Maxime , Iezzi Victor Lambin , Vincelette André , Bussières-Hersir Marie-Hélène , Rochette Martin
Published: January 2022

We report a 2 kW monolithic Yb-doped fiber laser with Raman filtering
within the resonant cavity. The laser is based on commercially
widespread 20 µm-core double-cladding fibers and laser diodes at a
wavelength of 915 nm.
Revealing the Relative Timing Jitter in Dual-Comb Laser Using Dispersive Fourier Transform
Authors: Prakash Neeraj , Li Bowen , Huang Shu-Wei
Published: January 2022

A technique for measuring relative timing jitter of a free-running
dual-comb system using the dispersive Fourier transform is
demonstrated. Insights about single-cavity dual-comb are presented,
showing the RIN noise effect on the relative timing jitter.
High-Energy Fe:ZnSe and Fe:ZnS Polycrystalline Lasers Longitudinally Pumped by HF Laser
Authors: Firsov Konstantin N. , Gavrishchuk Evgeny M. , Ikonnikov Vladimir B. , Savin Dmitry V. , Balabanov Stanislav S. , Kurashkin Sergey V. , Kononov Igor G. , Podlesnykh Sergey V.
Published: January 2022

The paper discusses the results of experimental studies of the
Fe2+:ZnSe and Fe2+:ZnS lasers based on
polycrystalline bulk active elements created using solid-state
diffusion bonding of pre-alloyed CVD-ZnSe(S) plates and hot isostatic
pressing method.
Spectroscopic and Laser Characterization of Color Centers in LiF Over More Than 20 Years Storage at Room Temperature
Authors: Subedi Shova , Fedorov Vladimir , Mirov Sergey
Published: January 2022

We present spectroscopic characterization of the laser active
LiF:F2+ and LiF:F2-
crystals over 20 years period. We demonstrated laser oscillations in
these crystals despite some degradation of the active centers.
Simultaneous Spectral Broadening and Contrast Improvement Using Divided-Pulse Nonlinear Compression
Authors: Jenkins Gregory W. , Feng Chengyong , Bromage Jake
Published: January 2022

We experimentally verify an analytic model that includes alignment
errors for the output pulse from divided-pulse nonlinear compression.
The model shows how divided-pulse nonlinear compression can
simultaneously broaden the pulse spectrum and improve the
contrast.
A Bidirectional Fiber Amplifier for Laser Phased Arrays Locked to a Remote Beacon
Authors: Srinivasan P. , Krogen P. , Meinhold P. , Ware A. B. , Hettel W. , Hughes G. B , Lubin P. M.
Published: January 2022

We demonstrate a Yb-doped fiber amplifier (YDFA) designed for large
aperture bidirectional laser phased arrays locked to a remote coherent
Beacon. The amplifier is CW, single-mode (λ = 1064
nm), gain of 30 dB, high slope efficiency of 86 ±
2.2% extremely large dynamic range > 100 dB and
broad temperature range with low residual phase noise of
≤ 30 mrad when the array is phase locked to the
Beacon.
Demonstration of Precision Phase Locking of a Laser Phased Array to a Weak Remote Beacon
Authors: Srinivasan P. , Krogen P. , Suen J. , Hettel W. , Ware A. B. , Meinhold P. , Hughes G. B. , Lubin P. M.
Published: January 2022

We demonstrate a sparse 3-channel Laser Phased Array (40 dBm/ch) locked
to an ultra low-power (-55 dBm/ch) remote Beacon. We measured a
combination efficiency ≥ 17% and 12
µs to peak power. In a nominal closed packed array
the combining efficiency is about 62%. This demonstration is a key
step in realizing directed energy for space applications.
Impact of purification on the optical properties of oxyfluoride glass ceramics for laser cooling applications
Authors: Thomas Jyothis , Meyneng Thomas , Ledemi Yannick , Seletskiey Denis , Messaddeq Younès , Kashyap Raman
Published: January 2022

Ytterbium-doped transparent oxyfluoride glass-ceramics (GCs) were
fabricated via traditional melt-quenching route for laser cooling
applications. A significant enhancement in photoluminescence (PL)
emission, quantum yield and PL lifetime is reported highlighting the
impact of purification using chelated assisted extraction
technique.
Simultaneous High-Speed Absorptance and Depth Monitoring in Scanning Laser Processing
Authors: Allen Troy R. , Fraser James M.
Published: January 2022

High-speed (100 kHz–1 MHz) in situ tracking of
laser-metal processing significantly benefits development of
deterministic models. We integrate inline coherent imaging with
integrating sphere radiometry to simultaneously measure keyhole depth
and absorp-tance during kW-laser processing (scan speed 50 mm/s).
Comparison of Ultrafast Laser Welding at 1030 and 515 nm
Authors: Guo Z. , Scott R. E. , Dorrer C. , Qiao J.
Published: January 2022

Experimental results are compared for laser interaction with
Borofloat-33 using femtosecond pulses at 1030 nm and 515 nm. Greater
heat affected zone and bonding strength are demonstrated at
515-nm.
Laser NL740 for LIDT application
Authors: Kudaba Giedrius
Published: January 2022

EKSPLA introduced NL740 nanosecond tunable pulse duration SLM laser
having superior pulse energy, longitudinal and special mode
stabilities. The set of output parameters shown itself as highly
suitable for LIDT applications.
Investigation of the Optical Gain in a Compact Ho3+:YAG MOPA System
Authors: Goth Katharina , Griesbeck Michael , Eitner Madeleine , Büker Hendrik , Eichhorn Marc , Kieleck Christelle
Published: January 2022

We report on the gain properties of a Ho3+:YAG MOPA system
pumped by a Tm3+ fiber laser with an amplifier slope
efficiency of 33.6%. The gain of the compact MOPA is studied for
varying pump and oscillator powers.
Vortex Coherent Beam Combining
Authors: Jabczynski Jan K. , Gontar Przemyslaw , Gorajek Lukasz , Zendzian Waldemar , Kopczyński Krzysztof
Published: January 2022

We propose Coherent Beam Combining with vortex wavefront to create an
effective optical trap. More than 50 dB barrier height (wall to center
irradiance ratio) for 127-hexagonal lattice was shown in numerical
model.
Spectra of Optical Discharge Plasma Propagating through Hollow-Core Fiber
Authors: Bufetov I.A. , Kolyadin A.N. , Yatsenko Y.P. , Kosolapov A.F.
Published: January 2022

Time-averaged plasma radiation spectra of an optical discharge
propagating through a hollow-core fiber under the action of pulse
laser radiation were determined. These spectra enable one to estimate
the plasma temperature as (13-17) kK.
Dark-line laser
Authors: To Bao-Dong , Wu Ming-Hsiung , Huang Yen-Chieh
Published: January 2022

We report an etalon-out-coupled laser that suppresses laser emission at
a few sharp spectral lines, called the dark lines, in the emission
background of the laser’s gain spectrum.
Phase locked short pulses generation in a driven laser cavity
Authors: Englebert Nicolas , Arabí Carlos Mas , Parra-Rivas Pedro , Gorza Simon-Pierre , Leo François
Published: January 2022

We demonstrate theoretically and experimentally the existence of
temporal solitons in a driven laser pumped below its oscillation
threshold. Thanks to the cavity detuning, we show that ultra-short,
high-power pulses can be generated.
Direct Amplification Based on Yb:CALGO of High Average Power
Authors: Bai Chuan , Wang Geyang , Tian Wenlong , Zheng Li , Zhang Dacheng , Zhu Jiangfeng , Wei Zhiyi
Published: January 2022

We report on an investigation of the Yb:CALGO multi-pass amplifier.The
optical-to-optical efficiency 13.6% for 16 W absorbed pumping was
obtained for a double pass configuration, and 25% for the four pass
configuration.
Sub 180-fs mJ-level Yb:CALYO Diode Bar Pumped Regenerative Amplifier
Authors: Petrov Lyuben S. , Georgiev Kaloyan , Trifonov Anton , Xu Xiaodong , Xu Jun , Buchvarov Ivan
Published: January 2022

We report Yb:CaYAlO4 regenerative amplifier providing 177 fs
output pulses with 1.1 mJ energy and 0.5-1 kHz repetition rate at 1040
nm. Single Yb:crystal in TEM00 resonator was pumped by a
single diode bar.
Optical Single Bragg Mirror Filters for Silicon Multilayered Structure in Visible Wavelength Spectrum
Authors: Islam Md. Sakibul
Published: January 2022

A distributed Bragg reflector is designed to get an optical reflectance
on visible electromagnetic spectrum i.e., ~800 nm in this work. Device
is realized based on Abele’s matrix for TE mode.
Optical Characterisation of High Performance Laser Optics
Authors: Quinn Gary , Ertel Klaus , De Vido Mariastefanio , Clarke Danielle
Published: January 2022

We report on the experimental characterisation of 45° high reflectance
(HR) mirrors including scatter and transmittance measurements for use
in a 1kW average power pulsed laser system.
Temporal self-compression of high-energy near IR femtosecond pulses in KDP crystal
Authors: Mironov Sergey , Khazanov Efim
Published: January 2022

Numerically demonstrated a possibility to use KDP crystal for
simultaneous spectrum broadening and temporal self-compression of high
energy near infrared femtosecond pulses.
Partial Amplification Of Supercontinuum Radiation In The Spectral Region 1.5-2 μm
Authors: Zhluktova I.V. , Zverev A.D. , Kamynin V.A. , Trikshev A.I. , Sysoliatin A.A. , Tsevtkov V.B.
Published: January 2022

Generation of a supercontinuum with a maximum optical spectrum width of
about 1420 nm at a -30 dB level is presented. For amplification in the
spectral range of 1.5-2 mm, various amplifiers doped with ions such as
erbium, thulium, or holmium were used. The maximum output power was
614 mW after used the holmium-doped fiber amplifier.
Ultra-compact and ultra high–Q photonic chip based optical reference cavity at 1550nm
Authors: Pavlov Nikolay G. , He Jijun , Wang Rui N. , Liu Junqiu , Raja Arslan S. , Lihachev Grigory , Phelan Richard , Kippenberg Tobias J. , Jost John D.
Published: January 2022

We demonstrate a fully packaged compact optical reference cavity based
on a high-Q crystalline CaF2 microresonator. Two
commercially available lasers were stabi-lized to this reference with
linewidth reduction down to the sub-kHz level.
Versatile, do-it-yourself, low-cost spinning disk confocal microscope
Authors: Halpern Aaron R. , Lee Min Yen , Howard Marco D. , Woodworth Marcus A. , Nicovich Philip R. , Vaughan Joshua C.
Published: January 2022

Confocal microscopy is an invaluable tool for 3D imaging of biological specimens, however, accessibility is often limited to core facilities due to the high cost of the hardware. We describe an inexpensive do-it-yourself (DIY) spinning disk confocal microscope (SDCM) module based on a commercially fabricated chromium photomask that can be added on to a laser-illuminated epifluorescence microscope. The SDCM achieves strong performance across a wide wavelength range (∼400-800 nm) as demonstrated through a series of biological imaging applications that include conventional microscopy (immunofluorescence, small-molecule stains, and fluorescence in situ hybridization) and super-resolution microscopy (single-molecule localization microscopy and expansion microscopy). This low-cost and simple DIY SDCM is well-documented and should help increase accessibility to confocal microscopy for researchers.
Impact of Feedback Phases on the Dynamics of a Laser with Double Optical Feedback
Authors: de Mey Robbe , Jolly Spencer W. , Virte Martin
Published: January 2022

In simulating a semiconductor laser subject to two feedback loops, we observed the dynamics to be dependent on both feedback phases. Even for very low second feedback strength, the second phase has a visible influence.
Mutli-variable Optimization of Cooling of Mechanical Mode assisted by Three-level System
Authors: Vij Neelesh Kumar , Khosla Meenakshi , Gupta Shilpi
Published: January 2022

We develop, both analytically and numerically, an optimization scheme for ground-state cooling of a mechanical mode, over a broad range of system parameters using master equation approach, by coupling to a general three-level system.
Femtosecond Laser Ferroelectric Domains Reversal in Monodomain Calcium Barium Niobate Crystal
Authors: Mazur Leszek Mateusz , Liu Shan , Chen Xin , Krolikowski Wieslaw , Sheng Yan
Published: January 2022

Femtosecond pulses are used for the first time to invert spontaneous polarization in the monodomain calcium barium niobate crystal. The resulting domain patterns allow transverse SHG without the nonlinear noise encountered in multidomain crystals.
Deep Learning Assisted Classification of Noisy Laguerre Gaussian Modes
Authors: Raskatla Venugopal , Kumar Vijay
Published: January 2022

A deep learning assisted scheme for classification of noisy LG modes is proposed. This model is noise and alignment independent and will increase the accuracy and fidelity of OAM mode detection systems.
Integrated Silicon Resonator with Bragg Grating Reflectors for Passive Reservoir Computing
Authors: Mandalawi Younus , Das Ranjan , Schneider Thomas
Published: January 2022

We design a novel integrated silicon photonic resonator with Bragg grating reflectors for passive reservoir computing. It provides chaotic signal mixing and fading memory feature, which are imperative to solve time-dependent heavy computational tasks.
Quantum Differencial Interference Contrast microscopy
Authors: Urrego Daniel F. , Passos M. H. M. , Torres Juan P.
Published: January 2022

We present here the experimental demonstration of a Differential Interference Contrast microscope that makes use of the Hong-Ou-Mandel effect, a phenomenon genuinely quantum, for phase retrieval of phase objects.
Machine Learning-based Fiber-Wireless Channel Estimation
Authors: Pereira Luiz Augusto Melo , Mendes Luciano Leonel , Junior Arismar Cerqueira Sodré
Published: January 2022

This work reports a fiber-wireless (FiWi) channel estimation, using machine learning (ML). Numerical results demonstrate the ML potential for channel estimation considering a flat optical channel response and a fast-fading wireless channel.
Ultrashort Pulse Measurement at 1.9 µm Using GRENOUILLE Technique
Authors: Vlasov D.S. , Voropaev V.S. , Batov D.T. , Aktürk S. , Jafari R. , Tarabrin K. M. , Trebino R. , Lazarev V. A.
Published: January 2022

We demonstrate the features of the GRENOUILLE technique for measuring the amplitude-phase characteristics of ultrashort pulses at a wavelength of 1.9 µm for pulses with a duration of 330 fs and about 70 fs.
Optimum Pattern Depth for Diffraction in Phase Gratings
Authors: Haldar Arpita , De Dhananjoy , Vijaya R.
Published: January 2022

In 1-D step grating, the diffraction intensity is a monotonic function of the refractive index. But in a 2-D arrangement, an optimum pattern depth is possible and this is a function of the refractive index.
Near-maximal Polarization Entanglement for Quantum Communications at 2.1 µm
Authors: Dada Adetunmise C. , Kaniewski Jedrzej , Gawith Corin , Lavery Martin , Hadfield Robert H. , Faccio Daniele , Clerici Matteo
Published: January 2022

We demonstrate for the first time a positive secure-key rate at 2.1 µm (0.417 bits/pair, with a quantum bit error rate of 5.43%), using near-maximally entangled photons in a proof-of-principle device-independent quantum-key-distribution scenario.
Wave Propagation and Imaging using Thin Lens under Effect of Chirality and Dielectric Loss
Authors: Muntaser Akram , Chatterjee Monish R
Published: January 2022

In this paper, we study the propagation of p-polarized electromagnetic waves across a chiral thin lens using ABCD matrix to examine the propagation and imaging of a transverse object under dielectric loss and variable chirality.
Demonstration of a Multi-Channel Dynamic Interrogation System based on Matched Filters for Elastic Wave Sensing
Authors: K. Aananth , Jagadeeshwar Tabjula L , Srinivasan Balaji
Published: January 2022

We experimentally demonstrate a dual-channel dynamic interrogator for elastic waves sensing using matched fiber Bragg gratings, with noise floor closer to theoretical limit using hardware filtering and computationally inexpensive signal conditioning.
Non-diffractive Beam Cleaving of Fibers for Optical Connectivity
Authors: Yuan Lei , McClure Randy , Carberry Joel , Terwilliger Chad , Ungaro Craig , Meek David , Bickham Scott , Wang Hanzheng , Liu Jie , Wu Qi
Published: January 2022

We present our recent progress on non-diffractive beam cleaved fibers for optical connectivity applications. Fiber/ribbon can be cleaved at flexible locations with no swelling, flat end face, controlled surface roughness, and high process throughput.
Practical Considerations For 1x4 All-Fiber MMI Based Power Splitter Using Square Core Fiber
Authors: Srivastava K. , Bhatia N.
Published: January 2022

We investigate the practical issues such as fiber offset and operational band- width for 1x4 all-fiber square core multimode interference based optical power splitter.
Computational adaptive optics for high-resolution non-line-of-sight imaging
Authors: Ou Zhan , Wu Jiamin , Yang Yuhao , Zheng Xiaoping
Published: January 2022

Non-line-of-sight (NLOS) imaging has aroused great interest during the past few years, by providing a unique solution for the observation of hidden objects behind obstructions or scattering media. As such, NLOS imaging may facilitate broad applications in autonomous driving, remote sensing, and medical diagnosis. However, existing NLOS frameworks suffer from severe degradation of resolution and signal-to-noise ratio (SNR) due to aberrations induced by scattering media and system misalignment, restricting its practical applications. This paper proposes a computational adaptive optics (CAO) method for NLOS imaging to correct optical aberrations in post-processing without the requirement of any hardware modifications. We demonstrate the effectiveness of CAO with a confocal NLOS imaging system in Terahertz (THz) band by imaging different samples behind occlusions for both low- and high-order aberrations. With appropriate metrics used for iterative CAO in post-processing, both the resolution and SNR can be increased by several times without reducing the data acquisition speed.
46.4 Gbps visible light communication system utilizing a compact tricolor laser transmitter
Authors: Hu Junhui , Hu Fangchen , Jia Junlian , Li Guoqiang , Shi Jianyang , Zhang Junwen , Li Ziwei , Chi Nan , Yu Shaohua , Shen Chao
Published: January 2022

Visible light communication (VLC), combining wireless communication with white lighting, has many advantages. It is free of electromagnetic interference, is rich in spectrum resources, and has a gigabit-per-second (Gbps) data rate. Laser diodes (LDs) are emerging as promising light sources for high-speed VLC communication due to their high modulation bandwidth. In this paper, we demonstrate a red/green/blue (R/G/B) LDs based VLC system with a recorded data rate of 46.41 Gbps, employing discrete multitone (DMT) and adaptive bit-loading technology to achieve high spectral efficiency (SE). The emission characteristics and transmission performance of R/G/B-LDs are discussed. The optimal data rates of R/G/B-LDs channels are 17.168/14.652/14.590 Gbps, respectively. The bit-error-ratio (BER) of each channel satisfies the 7% forward-error-correction (FEC) threshold (3.8×10−3) and greatly approaches the channel Shannon limit.
Physically-secured high-fidelity free-space optical data transmission through scattering media using dynamic scaling factors
Authors: Xiao Yin , Zhou Lina , Pan Zilan , Cao Yonggui , Chen Wen
Published: January 2022

In this paper, we propose a method of physically-secured high-fidelity free-space optical data transmission through scattering media using physically- and dynamically-generated scaling factors. Optical channel characteristics are explored, and scaling factors are physically and dynamically generated to serve as security keys in the developed free-space optical data transmission system. The generated dynamic scaling factors provide a security layer for free-space optical data transmission. To the best of our knowledge, it is the first time to physically and dynamically generate scaling factors in free-space optical data transmission system to realize data encryption. The scaling factors existing in free-space optical data transmission channel are physically and dynamically controlled by using two optical devices, i.e., variable beam attenuator (VBA) and amplitude-only spatial light modulator (SLM). Nonlinear and dynamic variation of scaling factors is realized in different free-space wave propagation environments. It is experimentally demonstrated that high security can be guaranteed in the developed physically-secured high-fidelity free-space optical data transmission system, since one random scaling factor is physically and dynamically generated for the transmission of each signal pixel value. In addition, the proposed physically-secured free-space optical data transmission scheme is robust to noise and scattering, and high-fidelity signals are retrieved at the receiving end. The proposed method could open up a new research perspective for the secured free-space optical data transmission.
1-GHz dual-comb spectrometer with high mutual coherence for fast and broadband measurements
Authors: Voumard T. , Darvill J. , Wildi T. , Ludwig M. , Mohr C. , Hartl I. , Herr T.
Published: January 2022

Dual-frequency comb spectroscopy permits broadband precision spectroscopy with high acquisition rate. The combs’ repetition rates as well as the mutual coherence between the combs are key to fast and broadband measurements. Here, we demonstrate a 1-GHz high-repetition-rate dual-comb system with high mutual coherence (sub-Hz heterodyne beatnotes) based on mature, digitally controlled, low-noise erbium-doped mode-locked lasers. Two spectroscopy experiments are performed with acquisition parameters not attainable in a 100-MHz system: detection of water vapor absorption around 1375 nm, illustrating the potential for fast and ambiguity-free broadband operation, as well as acquisition of narrow gas absorption features across a spectral span of 0.6 THz (600 comb lines) in only 5

μ

s.
Clustering-based data detection for spectral signature multiplexing in multispectral camera communication
Authors: Moreno Daniel , Guerra Victor , Rufo Julio , Rabadan Jose , Perez-Jimenez Rafael
Published: January 2022

Optical camera communication (OCC) is a promising technology to be used in future wireless communication systems. In this work, a cluster-based data detection procedure is applied to enhance the performance of an OCC system. A multispectral camera is employed to capture the spectral variations in light-emitting diodes (LEDs) caused by temperature. This strategy’s system performance is compared with a system that uses traditional linear methods, such as zero-forcing (ZF) and minimum mean square error (MMSE) equalizers. The findings of this study indicate that an improvement in the bit error rate (BER) can be achieved by applying a clustering approach.
Spatial separation of azimuthally and radially polarized beams from non-polarized light waves based on the electrically controlled birefringence effect
Authors: Chen Mingce , Li Zhexun , Liu Taige , Wang Zhe , Chen Zhaomin , Liu Kewei , Hu Chai , Ye Mao , Shi Jiashuo , Zhang Xinyu
Published: January 2022

Based on the electrically controlled birefringence effect in liquid crystal materials, an effective method for spatially separating azimuthally and radially polarized beams from non-polarized incident light waves is proposed. The radially polarized beam was highly converged by using a microhole-patterned electrode and a planar photo-alignment layer to shape the initial liquid-crystal radial alignment and a gradient refractive index distribution with central axial symmetry after applying a voltage signal. Due to the intrinsic polarization sensitivity of nematic liquid-crystal materials, the shaped gradient refractive index only applies to extraordinary light waves, which then converge into a spot. Thus, the azimuthally and radially polarized beams are effectively separated. The proposed method demonstrates some advantages, such as low cost, miniaturization, and easy fabrication and integration with other functional devices. Thanks to the wideband electrically controlled birefringence of liquid-crystal materials, this light-wave manipulation to spatially separate azimuthally and radially polarized beams can also be performed over a wide wavelength range.
Fiber-optic joint time and frequency transmission with enhanced time precision
Authors: Zuo Faxing , Li Qi , Xie Kunfeng , Hu Liang , Chen Jianping , Wu Guiling
Published: January 2022

We propose a high-precision joint time and frequency transmission scheme based on bidirectional wavelength division multiplexing transmission over an optical fiber link. The time signal is generated based on the phase-stable frequency signal with employment of a dedicated designed low-jitter event generator. Time synchronization is realized by eliminating the time difference between the time signals of the master and slave stations, which is determined by accurate two-way time comparison. In this way, thanks to the high stability of the frequency transmission, low jitter of the dedicated designed event generator, and the high accuracy of the two-way time comparison, a high precision time signal with enhanced time stability and accuracy can be obtained at the slave station, which is synchronized to the master station. Experimentally, a joint time and frequency transmission system is demonstrated over a 62-km urban fiber link. The results show a time stability in terms of time deviation (TDEV) of 3.5 ps/s and 430 fs/10,000 s, and an accuracy of better than 20 ps can be realized.
Evolution enhances mutational robustness and suppresses the emergence of a new phenotype: A new computational approach for studying evolution
Authors: Kaneko Tadamune , Kikuchi Macoto
Published: January 2022

The aim of this paper is two-fold. First, we propose a new computational method to investigate the particularities of evolution. Second, we apply this method to a model of gene regulatory networks (GRNs) and explore the evolution of mutational robustness and bistability. Living systems have developed their functions through evolutionary processes. To understand the particularities of this process theoretically, evolutionary simulation (ES) alone is insufficient because the outcomes of ES depend on evolutionary pathways. We need a reference system for comparison. An appropriate reference system for this purpose is an ensemble of the randomly sampled genotypes. However, generating high-fitness genotypes by simple random sampling is difficult because such genotypes are rare. In this study, we used the multicanonical Monte Carlo method developed in statistical physics to construct a reference ensemble of GRNs and compared it with the outcomes of ES. We obtained the following results. First, mutational robustness was significantly higher in ES than in the reference ensemble at the same fitness level. Second, the emergence of a new phenotype, bistability, was delayed in evolution. Third, the bistable group of GRNs contains many mutationally fragile GRNs compared with those in the non-bistable group. This suggests that the delayed emergence of bistability is a consequence of the mutation-selection mechanism.
The COVID-19 alcohol paradox: British household purchases during 2020 compared with 2015-2019
Authors: Anderson Peter , O’Donnell Amy , Jané Llopis Eva , Kaner Eileen
Published: January 2022

British supermarket-panel data suggest no increases in overall sales and purchases of alcohol following COVID-19 lockdowns, yet survey and mortality data suggest otherwise. This paper attempts to unravel the paradox. Based on purchase data of 79,417 British households from Kantar Worldpanel, we undertake controlled interrupted time series analysis of the impact of COVID-19 confinement introduced on 23rd March 2020, and variably applied during 2020, compared to purchases during 2015 to 2019 as controls. We also undertook Poisson regression analyses to estimate if changes in purchases differed by household socio-demographic and economic factors. Excess off-trade household alcohol purchases (expressed as grams of ethanol) following the introduction of confinement, were 29.2% higher (95% CI = 25.8% to 32.5%) for the post-confinement months of 2020, being larger until mid-July 2020 (37.5%, 95%CI = 33.9 to 41.26%) when pubs re-opened with restrictions, and smaller (24.6%, 95%CI = 21.6 to 27.7) thereafter. During the time of complete pub closures, and fully adjusting for no on-trade purchases, household purchases of alcohol did not change when compared with the same time period during 2015–2019 (coefficient = -0.9%, 95%CI = -5.6 to 3.8). Excess purchases from 23rd March to 31st December 2020 varied by region of Great Britain, being higher in the north of England, and lower in Scotland and Wales. Excess purchases were greater in the most deprived households, compared with the least deprived households. Excess purchases increased substantially as the amount of alcohol normally purchased by a household increased, with the top one fifth of households that normally bought the most alcohol increasing their purchases more than 17 times than the bottom one fifth of households that bought the least alcohol. That the heaviest buyers of alcohol increased their purchases the most, with some independent impact of socio-economic disadvantage, might explain why reported alcohol problems and recent alcohol-related death rates might have increased. A conclusion of this is that alcohol policy to reduce high consumption of alcohol, and the availability of help and treatment to reduce alcohol consumption become more important during extraordinary times, such as COVID lockdowns.
Novel insights into Pinus species plastids genome through phylogenetic relationships and repeat sequence analysis
Authors: Zeb Umar , Wang Xiukang , Fiaz Sajid , Azizullah Azizullah , Shah Asad Ali , Ali Sajjad , Rahim Fazli , Ullah Hafiz , Leghari Umed Ali , Wang Weiqiang , Nawaz Taufiq
Published: January 2022

Pinus is one of the most economical and ecological important conifers, model specie for studying sequence divergence and molecular phylogeney of gymnosperms. The less availability of information for genome resources enable researchers to conduct evolutionary studies of Pinus species. To improve understanding, we firstly reported, previously released chloroplast genome of 72 Pinus species, the sequence variations, phylogenetic relationships and genome divergence among Pinus species. The results displayed 7 divergent hotspot regions (trnD-GUC, trnY-GUA, trnH-GUG, ycf1, trnL-CAA, trnK-UUU and trnV-GAC) in studied Pinus species, which holds potential to utilized as molecular genetic markers for future phylogenetic studies in Pinnus species. In addition, 3 types of repeats (tandem, palindromic and dispersed) were also studied in Pinus species under investigation. The outcome showed P. nelsonii had the highest, 76 numbers of repeats, while P. sabiniana had the lowest, 13 13 numbers of repeats. It was also observed, constructed phylogenetic tree displayed division into two significant diverged clades: single needle (soft pine) and double-needle (hard pine). Theoutcome of present investigation, based on the whole chloroplast genomes provided novel insights into the molecular based phylogeny of the genus Pinus which holds potential for its utilization in future studies focusing genetic diversity in Pinnus species.
Quantitative, traceable determination of cell viability using absorbance microscopy
Authors: Babakhanova Greta , Zimmerman Stephen M. , Pierce Laura T. , Sarkar Sumona , Schaub Nicholas J. , Simon Carl G.
Published: January 2022

Cell viability, an essential measurement for cell therapy products, lacks traceability. One of the most common cell viability tests is trypan blue dye exclusion where blue-stained cells are counted via brightfield imaging. Typically, live and dead cells are classified based on their pixel intensities which may vary arbitrarily making it difficult to compare results. Herein, a traceable absorbance microscopy method to determine the intracellular uptake of trypan blue is demonstrated. The intensity pixels of the brightfield images are converted to absorbance images which are used to calculate moles of trypan blue per cell. Trypan blue cell viability measurements, where trypan blue content in each cell is quantified, enable traceable live-dead classifications. To implement the absorbance microscopy method, we developed an open-source AbsorbanceQ application that generates quantitative absorbance images. The validation of absorbance microscopy is demonstrated using neutral density filters. Results from four different microscopes demonstrate a mean absolute deviation of 3% from the expected optical density values. When assessing trypan blue-stained Jurkat cells, the difference in intracellular uptake of trypan blue in heat-shock-killed cells using two different microscopes is 3.8%. Cells killed with formaldehyde take up ~50% less trypan blue as compared to the heat-shock-killed cells, suggesting that the killing mechanism affects trypan blue uptake. In a test mixture of approximately 50% live and 50% dead cells, 53% of cells were identified as dead (±6% standard deviation). Finally, to mimic batches of low-viability cells that may be encountered during a cell manufacturing process, viability was assessed for cells that were 1) overgrown in the cell culture incubator for five days or 2) incubated in DPBS at room temperature for five days. Instead of making live-dead classifications using arbitrary intensity values, absorbance imaging yields traceable units of moles that can be compared, which is useful for assuring quality for biomanufacturing processes.
A promising new tool for literacy instruction: The morphological matrix
Authors: Ng Melvin M. R. , Bowers Peter N. , Bowers Jeffrey S.
Published: January 2022

There is growing interest in the role that morphological knowledge plays in literacy acquisition, but there is no research directly comparing the efficacy of different forms of morphological instruction. Here we compare two methods of teaching English morphology in the context of a memory experiment when words were organized by affix during study (e.g., a list of words was presented that all share an affix, such as , , , , etc.) or by base during study (e.g., a list of words was presented that all share a base, such as , , , ). We show that memory for morphologically complex words is better in both conditions compared to a control condition that does not highlight the morphological composition of words, and most importantly, show that studying words in a base-centric format improves memory further still. We argue that the morphological matrix that organizes words around a common base may provide an important new tool for literacy instruction.
The comparison of catheter ablation on hard outcomes versus medical treatment for atrial fibrillation patients: A meta-analysis of randomized, controlled trials with trial sequential analysis
Authors: Song Jikai , Zhang Qinggang , Ye Lifang , Zheng Yaru , Wang Lihong
Published: January 2022

Background

The prevailing view is that ablation does not reduce the incidence of stroke and deaths in atrial fibrillation (AF), and guidelines suggest that long-term anticoagulation is required after ablation, regardless of the success of the procedure. We performed a meta-analysis of recent randomized, controlled trials (RCTs) to verify whether ablation compared with drugs reduced the incidence of stroke and deaths.

Methods

We systematically searched the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases for RCTs of AF catheter ablation (CA) compared to medical therapy (MT). The risk ratio (RR) and weighted mean difference (WMD) with 95% CIs were calculated using a random-effects model. A trial sequential analysis (TSA) was used to further validate the reliability of the primary outcomes.

Results

Seventeen RCTs were included, comprising 5,258 patients (CA, n = 2760; MT, n = 2498). Compared with medical therapy, CA was associated with a reduction in stroke/transient ischaemic attacks (TIAs) (p = 0.035; RR = 0.61 [95% CI, 0.386 to 0.965]; I2= 0.0%) and deaths (p = 0.004; RR = 0.7 [95% CI, 0.55 to 0.89]; I2= 0.0%). CA was associated with improvement in left ventricular ejection fraction (LVEF) (p = 0.000; WMD = 5.39 [95% CI, 2.45 to 8.32]; I2= 84.4%) and the rate of maintenance of sinus rhythm (SR) (p = 0.000; RR = 3.55 [95% CI, 2.34 to 5.40]; I2= 76.7%).

Conclusions

CA for AF had more favourable outcomes in terms of stroke/TIAs, deaths, change in LVEF, and the maintenance of SR at the end of follow-up compared to MT. Besides, the TSA results supported this conclusion.
‘Signal integrity’ in the Audiovisual Media Services Directive: Process, positions and policies examined and explained
Authors: Afilipoaie Adelaida , Dewaele Steven , Donders Karen
Published: January 2022

Technological convergence has pushed the broadcasting value chain into a state of imbalance. The updated Audiovisual Media Services Directive with its provision on signal integrity attempts to recalibrate the power relations in the value chain while also aspiring to achieve cultural objectives. By triangulating qualitative research methods, we investigate what signal integrity is from a legal and technical perspective, we identify the cases in which signals are protected and determine stakeholder positions. Our main finding is that signal integrity’s scope might be larger than envisaged by the European Commission but needs to be more carefully pinned down to ensure consistency of definition, interpretation and application across Member States. Furthermore, while protecting signal integrity supposedly serves a combined economic and cultural agenda, it mainly serves broadcasters’ financial interests. However, since broadcasters invest most in general interest and original content, this kind of economic protectionism could be justifiable.
The Future of Cultural Policies, Phillippe Kern (2020)
Authors: Kolokytha Olga
Published: January 2022

Review of: The Future of Cultural Policies, Phillippe Kern (2020)

Brussels: Les Editions KEA, 104 pp.,

ISBN 978-2-96019-921-5, p/bk, €20
Militancy, feminism and cinema: The case of Grupo Feminista Miércoles
Authors: Cervera Ferrer Lorena
Published: January 2022

This article contextualizes and characterizes the Venezuelan feminist film collective Grupo Feminista Miércoles. Founded by Venezuelan Josefina Acevedo and Italians Franca Donda and Ambretta Marrosu, among others, Grupo Feminista Miércoles (1979–88) produced the documentary Yo, tú, Ismaelina (‘I, you, Ismaelina’) () and the videos Argelia Laya, por ejemplo (‘Argelia Laya, for example’) (), Eumelia Hernández, calle arriba, calle abajo (‘Eumelia Hernández, up and down the street’) () and Una del montón (‘One of the bunch’) (), and participated in several activities organized by the Venezuelan women’s movement. On the one hand, this article pays attention to both the cinematic and political contexts that allowed the emergence of this collective, with a focus on the influence that Italian cinematic and feminist ideas had in these contexts. On the other hand, it also provides formal analysis of the collective’s filmography and explores how feminist ideas and praxis are deployed in its films. The overall aim of this article is to restore the contributions of Grupo Feminista Miércoles to both Latin American political cinema and transnational feminist cinema.