Optics - Science topic

Master 2 internship in nanophotonic. Experimental and theoretical work on the manipulation of optical surface wavepackets inside nanostructured gold films.

Raman and PL (photoluminescence) spectroscopy are effective techniques for characterizing the physical properties of transition metal dichalcogenides (TMDCs). Modulating intensities of these optical signals is crucial for the advancement of research and the subsequent application of TMDCs. However, it is challenging to continuously modulate optical...

Multiplexed optical data storage with the merits of a long lifetime and high data capacity is considered to be a promising technology for storing huge amounts of data generated by human activities. However, practical applications have been limited by the current data capacity, which remains at just a few terabytes (TB) per disc. Here, we demonstrat...

To perform holographic three-dimensional (3D) imaging and quantitative phase imaging with daily-use light, I developed a self-reference digital holography unit that is adaptable to an optical microscope with a light-emitting diode. The developed unit is combined with a commercially available optical microscope to implement a speckleless digital hol...

Detailed simulations have been undertaken of the dynamical response of linear and triangular arrays of nano-lasers to external optical feedback from a common external mirror. Careful attention is given to forms of dynamics that arise in such devices when experimentally accessible parameters such as the optical feedback strength, laser bias current,...

One of the appealing areas for fundamental research from the perspective of materials science is the influence of dynamic shock waves on crystals and the study of their structural responses. In the current work, we have reported the impact of shock waves on technologically important lithium sulphate monohydrate (LSM) single crystal with (101) orien...

The double-slit interference experiment has long been regarded as a cornerstone of the wave theory of light. However, optical interference patterns are absent in everyday life, prompting many scientists to question the validity of the experiment under specific conditions. Until now, no experiments have definitively challenged this theory. Here, we...

Bottom-up nano- to micro-fabrication is crucial in modern electronics and optics. Conventional multi-scale array fabrication techniques, however, are facing challenges in reconciling the contradiction between pursuit of better device performance...

We present experiments on reservoir computing (RC) using a network of vertical-cavity surface-emitting lasers (VCSELs) that we diffractively couple via an external cavity. Our optical reservoir computer consists of 24 physical VCSEL nodes. We evaluate the system's memory and solve the 2-bit XOR task and the 3-bit header recognition (HR) task with b...

This work introduces a high-throughput setup for Raman analysis of various flowing fluids, both transparent and non-transparent. The setup employs a microfluidic cell, used with an external optical setup, to...

A frequency-doubling optoelectronic oscillator (OEO) with fundamental frequency signal cancellation based on a dual-polarization Mach–Zehnder modulator (DPol-MZM) is proposed and experimentally demonstrated. In the proposed structure, two different modulation modes can be utilized to realize the frequency-doubling OEO. One is the carrier-suppressed...

Cellulose nanocrystals (CNCs) have attracted considerable interest due to their optical properties, though their nonlinear optical behavior remains largely unexplored. In this paper, we investigate the second-order nonlinear optical (SONLO)...

Digital holography represents a pioneering frontier in optical imaging, intertwining cutting-edge computational approaches with sophisticated optical methodologies [...]

This work focuses on the incoherent and coherent combination of pulsed laser beams, building on previous research [1] that addressed the combination of continuous-wave laser beams. For the pulsed combination, we have focused on the temporal evolution of the combined intensity at the image plane. Simulation results show that at the pulse peak, the c...

In this paper, we propose a tunable optical filter with a high Q factor based on photonic crystal technology, achieving a Q factor of 442.85 using thin film lithium niobate technology. By proportionally adjusting the dimensions of the unit structure, this filter enables coarse tuning across the 1520–1570 nm range (C band). Furthermore, by utilizing...

This paper studies the properties of a new vortex beam called an anomalous hollow Hermite vortex beam (AHHVB) through a uniaxial crystal orthogonal to the optical axis. A propagation formula for the corresponding beam in a medium of uniaxial crystal is obtained. Based on the derived formula, we conducted some graphical calculations to investigate t...

We report a new and more precise Sellmeier equation obtained by using the analysis of quasi-phase-matching curves of the optical parametric generation (OPG) in 1D periodically poled LiTaO3 (1D-PPLT) of different grating periods.

We address the development of efficient neural network (NN)-based post-equalizers in long-haul coherent-detection dense wavelength-division multiplexing (DWDM) optical transmission systems. To achieve a high level of generalization of the NN-based equalizers, we propose to employ multi-task learning (MTL). MTL refers to a single shared machine lear...

A meta-lens array-based Shack-Hartmann wavefront sensor has been developed to break the limits imposed by the size and curvature of traditional micro-lenses, which significantly improves both sampling density and angular resolution of phase measurement. Metasurface advances the field of optical phase measurement to smaller-scale complex wavefront c...

A paraxial propagation of new vortex beam named anomalous hollow Hermite vortex beam (AHHVB) passing through a chiral medium is investigated in this paper. The analytical equation to describe the received intensity of the AHHVB transmitting in a chiral medium is derived. Using the obtained formula, we conducted numerical simulations to calculate an...

Nanomaterials with one-, two-, or three-dimensional structures have exhibited superior optical, electronic, magnetic, thermal, and mechanical properties compared to their bulk material counterparts [...]

A phytochemical investigation on the flesh fruits of atemoya led to the isolation of seven new kaurane type diterpenoids, (4S*,5S*,8S*,9R*,10S*,13R*,16R*)-16-hydro-18-nor-kauran-4,17-diol (1), (4S*,5S*,8S*,9R*,10S*,13R*,16S*)-18-nor-kauran-4,16,17-triol (2), (4S*,5S*,8S*,9R*,10S*,13R*,16S*)-17-acetoxy-18-nor-kauran-4,16-diol (3), (4S*,5S*,8S*,9R*,1...

Two-dimensional (2D) layered materials have recently gained significant attention and have been extensively studied for their potential applications in neuromorphic computing, where they are used to mimic the functions of the human brain. Their unique properties, including atomic-level thickness, exceptional mechanical stability, and tunable optica...

Fibre optic probe based Raman spectroscopy can deliver in vivo molecular compositional analysis of a range of diseases. However, some biological tissues exhibit high levels of fluorescence which limit the...

This study examines the behavior and tunability of plasmonic lenses created from arrays of nanoslits, applicable in sub-wavelength optical microscopy and other high-resolution imaging systems. We performed simulations on COMSOL Multiphysics to assess power flow and focal shifts in plasmonic lenses with differing slit designs, refractive indices, an...

This paper recovers the gap solitons in fiber Bragg gratings for the concatenation model that comes with Kerr-law of self-phase modulation by the usage of enhanced direct algebraic approach. A full spectrum of optical solitons are thus recovered. The existence criteria of such solitons, in the form of parameters constraints, that naturally emerged...

The paper presents studies related to the creation of an effective concentrator of infrared radiation. Using such concentrators, it will be possible to detect weak or long-distance infrared radiation. According to the authors, in this case, the use of concentrators with reflective surfaces is preferable to lens concentrators. In particular, a phoco...

The ligandless palladium-catalyzed Heck reaction of 4-ethenyl-3-methoxy-1-phenyl-1H-pyrazole and 2-([1,1′-biphenyl]-4-yl)-5-bromo-3,3-dimethyl-3H-indole gave the previously unreported 2-([1,1′-biphenyl]-4-yl)-5-[(E)-2-(3-methoxy-1-phenyl-1H-pyrazol-4-yl)ethenyl]-3,3-dimethyl-3H-indole in 45% yield. The compound was characterized using NMR, FT-IR sp...

The propagation of ultra-short light pulses in silica optical fibers is modeled by the short pulse equation. We introduce a nonlocal regularization of the problem and study the existence of solutions in a class of possibly discontinuous functions.

A bstract What does a black hole look like? In 1 + 3 spacetime dimensions, the optical appearance of a black hole is a bidimensional region in the observer’s sky often called the black hole shadow, as supported by the EHT observations. In higher dimensions this question is more subtle and observational setup dependent. Previous studies considered t...

The field of optical nanomaterials stands at the forefront of technological innovation, driving advancements across a spectrum of scientific disciplines and industries [...]

We report the detection of broad, flat-topped emission in the fine-structure lines of [Ne v ], [Ne vi ], and [O iv ] in mid-infrared spectra of the O9 V star 10 Lacertae obtained with James Webb Space Telescope/Mid-Infrared Instrument. Optically thin emission in these high ions traces a hot, low-density component of the wind. The observed line flux...

Dual-chirped optical parametric amplification (DC-OPA) is a variant of OPCPA used to produce intense ultrafast pulse. In this study, we comprehensively explore the quantitative relationship between non-collinear broadband PM geometry and linear chirp coefficients. Compared to OPCPA, non-collinear broadband DC-OPA demonstrates different design strat...

Binary superlattices (BNSLs) with unique configurations are of great interest, attributing to the interaction between two kinds of nanoparticles, providing potential applications in sensing, electronic and optical fields. Here, polystyrene...

For atoms having pairwise similar electronic configurations, Sb([Cd]5p³), Xe([Cd]5p⁶) and Bi([Hg]6p³), Rn([Hg]6p⁶), features in the energy dependences of integral (ICSs) and differential (DCSs) cross sections of electron elastic scattering are considered theoretically. The positions of the Ramsauer–Townsend minimum (RT) and the low-energy maxima in...

The bandwidth of the ±1-order Kelly sidebands of mode-locking fiber lasers is investigated for narrow terahertz (THz) signal generation. Four key factors influencing the bandwidth of Kelly sidebands are found and analyzed in detail. Then, a numerical model is presented for manipulating the parameters of the mode-locking fiber laser. Two mode-lockin...

Nobel laureate Charles Hard Townes is well known for his work in quantum electronics, which led to the invention of the maser and lasers. He was also a notable figure in astrophysics and astronomy, particularly recognized as the architect of the first high-resolution optical stellar interferometer.

The current paper recovers a variety of highly dispersive optical solitons with non–local form of self–phase modulation structure and having polarization–mode dispersion. Two integration approaches have made this retrieval successful. The soliton solutions are enlisted and presented with the parameter constraints that ensures their existence. A sho...

We report on the nonlinear temporal post-compression of 7 mJ sub-40 fs pulses from a commercial kHz Ti:sapphire laser down to a record 3.8 fs duration (sub-1.5 optical cycle) in a compact single-stage gas-filled multi-pass cell (MPC), with 60% overall compression efficiency.

Fiber Fabry-Perot (FFP) cavities with laser-machined mirrors combine exceptional optical properties with a rugged, miniaturized, inherently fiber-coupled design. Originally developed for research on quantum technologies, they have found applications far beyond that field and are now being used to realize miniaturized, mobile greenhouse gas analyser...

Two pairs of diastereomerically pure calix[4]arene phosphoric acid derivatives with ABHH and ABCH substitution patterns were synthesized via phosphorylation and phosphotropic rearrangement on the narrow rim. These new cone-shaped, inherently chiral calixarenes were tested as organocatalysts in the stereoselective aza-Diels–Alder reaction of imines...

The bidirectional propagation properties of partially coherent Laguerre–Gaussian (PCLG) beams under atmospheric turbulence and plasma were numerically investigated. The corresponding analytical formulas for the intensity distribution, effective beam width, and M2 factor of PCLG beams were derived by utilizing the generalized Collins integral formul...

TSWV ve TYLCV dayanımlı pembe domateslerin geliştirilebilmesi için belirli agronomik özelliklere sahip hatlar ilk olarak morfolojik markörler kullanılarak tespit edilmiştir. İstenilen morfo-fizyolojik özelliklere sahip 242 ıslah hattının TSWV ve TYLCV dayanıklılıkları moleküler markörler kullanılarak incelenmiştir. TSWV’ye dayanıklılık sağlayan Sw-...

The relentless pursuit of miniaturization in the field of photonics has led to the emergence of micro–nano optical devices as a cornerstone of modern technology [...]

We propose and demonstrate an experiment to explore the optical reception performance of an on-chip spatial optical receiver based on an inverse design under three distinct turbulent conditions. Experimental results demonstrate that the receiver achieved a maximum emission efficiency of 81% at 1530 nm, with fluctuations of less than 2 dB over the w...

We report the fabrication and characterization of a multi-core anti-resonant hollow core fiber with low inter-core coupling. The optical losses were 0.03 and 0.08 dB/m at 620 and 1000 nm, respectively, while the novel structure provides new insights into hollow core fiber design and fabrication.

Bu çalışmada, çoğunlukla basınçlı kap üretiminde kullanılmakta olan P265GH ve P355NH çelikler MAG kaynağı uygulanarak birleştirilmiştir. Elde edilen birleştirmelerin kaynak bölgelerinde, gözle (VT), radyografik (RT) ve ultrasonik (UT) muayeneler ile optik mikroskop, mikrosertlik, çekme, çentik darbe ve eğme incelemeleri gerçekleştirilmiştir. Gözle...

The authors review and classify existing approaches to detect enemy drones and ways to combat them. Existing prototypes of interceptor drones are also analyzed and conclusions are drawn regarding the range of tasks that are solved by artificial intelligence methods in Counter-Unmanned Aircraft Systems. Conclusions are drawn about the possible combi...

Modified Fresnel equations for the oblique incidence of plane elliptically polarized electromagnetic waves on a flat boundary of a non-absorbing isotropic gyrotropic medium have been obtained. We have taken into account the influence of near-surface inhomogeneity of the matter. The derived relationships allow determining the intensity, degree of el...

We study dependence of dipole-dipole interaction in dense Rb vapour on optical excitation. We measure the dipole-dipole contribution to the selective reflection spectrum of D2 line. Optical excitation is created by intense laser beam, which depletes the 5S1/2 population and decreases the dipole-dipole interaction, narrowing the observed spectrum. T...

The relevance of this problem is due to the possibility of studying the influence of processes inside a gradient lithium niobate crystal, which can improve the quality of signal transmission. The properties of gradient lithium niobate as a phase modulator of an optical signal are modeled. The differences in the behavior of a gradient modulator from...

Based on the seminal work by John T. Sheridan [1] we discuss the usefulness and validity of simple diffraction theories frequently used to determine and characterize optical holographic gratings. Experimental investigations obtained in recent years highlight the correctness of his analysis which favours an alternative approach over the most widely...