Photonics, Volume 8, Issue 9

The celebrated Gaussian Schell model source with its shift-invariant degree of coherence may be the basis for devising sources with space-variant properties in the spirit of structured coherence. Starting from superpositions of Gaussian Schell model...

The assessment of dermal alterations is necessary to monitor skin aging, cancer, and other skin diseases and alterations. The gold standard of morphologic diagnostics is still histopathology. Here, we proposed parameters to distinguish morphologicall...

A plasma photonic crystal (PPC) was formed using an array of discharge plasma tubes. The transmission spectra and bandstructure of PPCs with different lattice types under different polarization modes were studied through simulation and measurement. T...

As optical performance monitoring (OPM) requires accurate and robust solutions to tackle the increasing dynamic and complicated optical network architectures, we experimentally demonstrate an end-to-end optical signal-to-noise (OSNR) estimation metho...

In this study, an emphasis is put on vapor-sensitive Bragg stacks as an important class of optical sensors. All-niobia Bragg stacks were deposited by spin-coating of sol-gel Nb₂O₅ thin films alternated with mesoporous layers after proper design throu...

We propose a concurrent single-pixel imaging, object location, and classification scheme based on deep learning (SP-ILC). We used multitask learning, developed a new loss function, and created a dataset suitable for this project. The dataset consists...

Due to the fact that a millimeter-wave (MMW) has a strong ability to penetrate clothing, MMW holographic imaging technology can conduct a non-contact inspection of the human body’s surface. In recent years, personnel surveillance systems utilizing MM...

In optical communication systems, coherent detection is a standard method. The received signal enters the digital domain after passing through a time-interleaved analog-to-digital converter (TI-ADC). However, the time delay of the ADC brings noise in...

Detection of small moving objects in long range infrared (IR) videos is challenging due to background clutter, air turbulence, and small target size. In this paper, we present two unsupervised, modular, and flexible frameworks to detect small moving...

In this study, different coatings (gray epoxy primer, white epoxy varnish and red alkyd paint) of 7075 aluminum alloy are cleaned with a 500 W continuous-wave (CW) fiber laser. We analyzed the influence of the laser power density on the temperature e...

Temperature variation not only results in changes in refractive index, radius, thickness, and air space, but also leads to surface deformation due to the mismatch in thermal expansion coefficients between glass and mechanical materials. However, exis...

The collection of papers presented in this Special Issue (SI) portraits the state-of-the-art of photonic-based interferometric sensors, where new application areas were explored (such as spirometry) and novel sensitivity limits were achieved, using i...

Automation of milking systems is linked to accurate measurement of fluctuations in milk flow during milking. To assess the fluctuations of the milk flow, the formation and movement of milk portions in the milking machine-milk pipeline system was stud...

This paper introduces novel research in aquaphotomics, extending the study of water–light interactions to the visible spectral range. This approach can potentially reduce the cost and increase the speed of spectral measurements, while providing addit...

A compact and simple structure is designed to create an all-optical XOR logic gate using a two-dimensional, photonic crystal lattice. The structure was implemented using three waveguides connected by two nano-resonators. The plane wave expansion meth...

Spiral pattern is formed for coaxial interference between two vortex beams with different radii of wavefront curvatures and different topological charges (TCs). A theoretical model considering various parameters (such as phase difference, radius of w...

In this manuscript, an implementation of a tunable nonlinear phase compensation method is demonstrated on a typical femtosecond hybrid laser consisting of a fiber pre-amplifier and an additional solid-state amplifier. This enables one to achieve cons...

The statistics of the optical phase of the light emitted by a semiconductor laser diode when subject to periodic modulation of the applied bias current are theoretically analyzed. Numerical simulations of the stochastic rate equations describing the...

We present a theoretical and experimental study of photonic demultiplexers based on detuned stubs. The demultiplexers consist of Y-shaped structures with one input line and two output lines. Two different types of structures are proposed to achieve a...

In this paper, a three-layer GaAs photoconductive semiconductor switch (GaAs PCSS) is designed to withstand high voltage from 20 to 35 kV. The maximum avalanche gain and minimum on-state resistance of GaAs PCSS are 1385 and 0.58 Ω, respectively, whic...

In this study, the generation of energetic coherent extreme ultraviolet (XUV) radiation with the potential for controlled polarization is reported. The XUV radiation results from the process of high harmonic generation (HHG) in a gas phase atomic med...

Long-range surface plasmon resonance (LRSPR), generated from a coupled plasmon polariton in a thin metal slab sandwiched by two dielectrics, has attracted more and more attention due to its merits, such as longer propagation and deeper penetration th...

Photoacoustic (PA) spectroscopy techniques enable the detection of trace substances. However, lower threshold detection requirements are increasingly common in practical applications. Thus, we propose a systematic geometry topology optimization appro...

We proposed an aerial projection 3D display based on integral imaging. It is composed of a projector, a lens-array holographic optical element (HOE), and two parabolic mirrors. The lens-array HOE is a diffraction grating and is made by the volume hol...

Stimuli to excitable cells and various cellular processes can cause cell surface deformations; for example, when excitable cell membrane potentials are altered during action potentials. However, these cellular changes may be at or below the diffracti...

We investigate the optical amplification of the output field and fast-slow light effect in a three-mode cavity optomechanical system without rotating wave approximation and discuss two ways of realizing the optical amplification effect. Resorting to...

We report here an all-fiber structure tunable gas Raman laser based on deuterium-filled hollow-core photonic crystal fibers (HC-PCFs). An all-fiber gas cavity is fabricated by fusion splicing a 49 m high-pressure deuterium-filled HC-PCF with two soli...

Recent studies on image restoration (IR) methods under unrolled optimization frameworks have shown that deep convolutional neural networks (DCNNs) can be implicitly used as priors to solve inverse problems. Due to the ill-conditioned nature of the in...

The existence of aberrations has always been an important limiting factor in the imaging field. Especially in optical microscopy imaging, the accumulated aberration of the optical system and the biological samples distorts the wavefront on the focal...

Shaped optical fiber tips have recently attracted a lot of interest for photonic jet light focusing due to their easy manipulation to scan a sample. However, lensed optical fibers are not new. This study analyzes how fiber tip parameters can be used...

Laser bioprinting with gel microdroplets that contain living cells is a promising method for use in microbiology, biotechnology, and medicine. Laser engineering of microbial systems (LEMS) technology by laser-induced forward transfer (LIFT) is highly...

Graphene material, due to its unique conductivity and transparency properties, is utilized extensively in designing tunable terahertz perfect absorbers. This paper proposes a framework to design a tunable terahertz perfect absorber based on fractal t...

In recent years, fiber gas lasers have obtained a rapid development, however, efficient and stable pump coupling is a key limitation for their applications in the future. Here, we report an all-fiber gas cavity based on anti-resonant hollow-core fibe...

In this paper, to enhance practicality, a novel tapered thin-core fiber (t-TCF) based modal interferometer is proposed and demonstrated experimentally. The light field distribution of t-TCF structure is investigated by a beam propagation method, and...

Chirped and tilted fiber Bragg gratings (CTFBGs) have attracted a lot of attention in stimulated Raman scattering (SRS) suppression of high-power fiber lasers. However, the laser power handling capacity seriously limits their applications. In this pa...

In a coherent diffraction imaging (CDI) system, the information of the sample is retrieved from the diffraction patterns recorded by the image sensor via multiple iterations. The limited dynamic range of the image sensor restricts the resolution of t...

In this paper, dual-branch pre-distorted enhanced asymmetrically clipped direct current (DC) biased optical orthogonal frequency division multiplexing (PEADO-OFDM) for underwater optical wireless communication (UOWC) is firstly proposed and simulated...

A novel approach for precise determination of the optical scattering and absorption properties of porcine tissue using an optimized integrating sphere setup was applied. Measurements on several sample types (skin, muscle, adipose tissue, bone, cartil...

We present a theoretical study of the nonlinear dynamics of a long external cavity delayed optical feedback-induced interband cascade laser (ICL). Using the modified Lang–Kobayashi equations, we numerically investigate the effects of some key paramet...

Optical trapping of sub−micrometer particles in three dimensions has been attracting increasing attention in a wide variety of fields such as physics, chemistry, and biologics. Optical fibers that allow stable trapping of such particles are not readi...

We demonstrate a pruned high-speed and energy-efficient optical backpropagation (BP) neural network. The micro-ring resonator (MRR) banks, as the core of the weight matrix operation, are used for large-scale weighted summation. We find that tuning a...

In this paper, a novel and compact magnetic field sensor based on the combination of an optical microfiber coupler interferometer (OMCI) and magnetic fluid (MF) is proposed. The sensor is made up of an OMCI cover with polydimethylsiloxane (PDMS) and...

The best surface plasmon resonance (SPR) signal can be generated based on several factors that include the excitation wavelength, the type of metal used, and the thickness of the metal layer. In this study, the aforementioned factors have been invest...

A phase unwrapping method for phase-shifting projected fringe profilometry is presented. It did not require additional projections to identify the fringe orders. The pattern used for the phase extraction could be used for phase unwrapping directly. B...

Electromagnetic cloaking has being continuously pursued using a large variety of approaches. In recent years, this effect has been observed using either complex devices based on the so-called Transformation Optics or simple systems based on conventio...

The application bottleneck of laser welding is being gradually highlighted due to a high prevalence of porosity. Although laser welding technology has been well applied in fields such as vehicle body manufacturing, the suppression of weld porosity in...

Periodontal disease is the most common oral chronic inflammatory disease in humans. Recent studies have indicated that red light Photobiomodulation (PBM) could inhibit cell inflammation effectively, but the effect of different doses of PBM on the tre...

This paper aims to pave the way towards the demonstration of spatiotemporal similariton pulses’ evolution in passive multimode fibers with Raman amplification. We numerically present this issue in graded-index and step-index multimode fibers and prov...

The focusing of light through turbid media like biological tissues is strongly hindered by the scattering of light which limits its safe practice and application in medicine. In order to control this phenomenon, we shaped the incident wavefront using...

Photoacoustic computed tomography (PACT) is a fast-developing imaging technique, which can provide structural and functional information in biological tissues with high-resolution beyond the depth of the optical diffusion limit. However, the most cur...