The survivable logical topology mapping (SLTM) problem in IP-over-WDM networks is to map each link in the logical topology (IP layer) onto a lightpath in the physical topology (optical layer) such that a failure of a physical link does not cause the logical topology to become disconnected. This problem is known to be NP-complete. For this SLTM problem, two lines of investigations have been reported

Elastic optical networks (EONs) are a promising solution for future high-speed optical communication, and multicasting in EONs can efficiently support many emerging services. Different schemes, such as path, tree and subtree schemes, serve multicast services. In this paper, we consider a three-stage wavelength-space-wavelength (WSW) node architecture, which adopts wavelength switches in the first and

In the last twenty years, optical networks have witnessed recurrent changes in their management and control architecture. In this paper, we present an historical timeline and a future perspective of the evolution of optical network management and control deployed for Wavelength Switched Optical Networks (WSON), Elastic Optical Networks (EON) and (multilayer) Data Center Networks. Early implementations

We developed an amblyopia-training device, which can be used easily and inexpensively under binocular conditions with polarizing films. The device uses two polarizing films: one is attached to the training target (such as monitors and books), while the other is attached to the lens of glasses that cover the healthy eye with the absorption axis rotated 90 degrees. This allows the target to be presented

Telecom operators' infrastructure is sustained by optical communication networks that provide the means for exchanging large amounts of information, which is essential for many modern society needs. Optical networks are characterized by rapid breakthroughs in a variety of technologies. Relevantly, the last decade encompassed remarkable advances in optical networks’ subfields of signal processing, electronics

Color shift behavior at the edges of white-and-black line patterns was measured and analyzed for three raster-scan mobile projectors using the three-primary-color (red, green, blue) laser diodes. The 2D data of the line patterns projected on a standard diffusive reflectance screen were captured by a speckle measurement device for analyzing the effects of both the color speckle noise and the edge color

In this paper, we focus on the efficient dynamic routing in Spectrally-Spatially Flexible Optical Networks (ss-fon) realized using Single-Mode Fiber Bundles (smfbs). We study two scenarios – unprotected network (np) and network protected by dedicated path protection (dpp) against a single link failure. For these configurations, we propose a dedicated optimization approach (Enhanced Adaptive Spectral-Spatial

This paper describes the noise analysis of an electro-optic (EO) sensor system based on experimental and simulation results. We developed a polarization simulator of the EO sensor system using the Jones vector and matrix. The polarization simulator included not only the laser intensity noise but also the laser polarization noise. The polarization noise was converted into an intensity noise due to the

In this study, we established consecutive monitoring methods using UAV in pecan orchards of 64 ha each, in San Simon, Arizona, USA. Activity monitoring, tree height map creation and ground surface temperature analysis of trees by UAV with near infrared (NIR)/TIR camera were conducted for pecan orchards in San Simon, Arizona, USA. Using established continuous monitoring methods, the UAV images of a

Fringe projection profilometry (FPP) is a technique used for obtaining the three-dimensional shape of an object in fields such as reverse engineering, cultural heritage, and computer vision. The FPP measurement accuracy significantly depends on the arrangement of the measurement system, measurement space conditions, equipment setting, and object characteristics. However, experimental verification of

For ultra-compact near-eye display, waveguides provide a small form factor because they are thin shape plate, but projectors are too large due to the imaging sources, which results in bulky near-eye displays. Recent advances in fiber-scanning technology can overcome this limitation. Fiber-scasnning projectors produce an image by vibrating an optical fiber, and they can be small because only thin fibers

In this paper, we report the performance evaluation of praseodymium doped fiber amplifier (PDFA) operating in 1.25–1.35 μm band of wavelengths based on theoretical simulation. The performance of the PDFA is evaluated by considering an optimized length of Pr\(^{3+}\) doped fiber, concentration of Pr\(^{3+}\) ions and pump power. Moreover, the impact of input signal wavelength on gain, amplified spontaneous

The advent of Elastic Optical Networks (EON) has led to significant improvements in optical network spectrum utilization when compared to Wavelength Division Multiplexing Optical Networks. However, the EON brought challenges to be explored, notably the Power, Routing, Modulation Level and Spectrum Assignment (PRMLSA) problem. This article aims to explore techniques for the PRMLSA problem, being developed

Inter-core crosstalk causes severe signal impairment in Space Division Multiplexing Elastic Optical Networks (SDM-EON) with multi-core fibre (MCF). In order to mitigate the influence of crosstalk between cores, bidirectional MCF is used. SDM-EON has dramatically increased the network bandwidth and is the mainstream trend of future communications, but the overall cost of such an SDM-EON will increase

This paper proposes a novel joint resource allocation technique for flexible-grid systems by utilizing non-dominant sort genetic algorithm (NSGA-II) in a multi-objective optimization framework. It pioneers the implementation of an evolutionary mechanism to optimize resources as means of mitigation of physical layer impairments. This investigation initially introduces a proposal in which bandwidth reduction

To enhance the security in optical image encryption scheme and to safeguard it from the invaders, this paper proposes a new scheme using devil’s toroidal lens masks (DTLMs) and QR decomposition in gyrator transform (GT) domain. The proposed cryptosystem utilizes DTLMs which are the complex phase masks designed using the combination of a phases of devil’s mask (\({\rm DM})\) and toroidal mask \(\left({\rm

The double random phase encoding techniques have received considerable attention from researchers in recent years because of their advantages of parallel and high-speed processing capability. Meanwhile, the security of the cryptosystem is also one of the major concerns. We experimentally showed the ciphertext redundancy vulnerability of the coherent double random phase encryption (DRPE) system. Based

During endoscopic surgery, the operation accuracy can be improved if the endoscope system provides 3D information. In this paper, an adaptor lens is presented for a commercial 2D endoscope to generate stereoscopic images. The function of the adaptor lens is verified in this study, and we prove the adaptor lens can be compatible with an arbitrary rigid 2D endoscope system even if its original imaging

Next Generation Ethernet Passive Optical Network (NG-EPON) is considered to be future prospective access technology that could help to achieve 100Gbps data rates. Wavelength bonding is a phenomenon that can help Optical Network Units (ONU) to enhance their transmission capabilities. Using wavelength bonding, an ONU could transmit on multiple wavelength channels in parallel. The ONUs can achieve data

Generalized Kramers–Kronig (K–K) type dispersion relations and sum rules are derived in the static limit for the moments of the degenerate four wave mixing susceptibility. The degenerate nonlinear susceptibility is different from a typical use of the conventional K–K dispersion relations, which assume absence of complex poles of a function in the upper half of complex frequency plane, whereas degenerate

Heat-assisted magnetic recording (HAMR) is a promising technology with high recording density. The authors’ group has proposed a novel device for HAMR, in which a metal nano-antenna as a near-field transducer is attached to a semiconductor ring resonator as a light source. The ring resonator oscillation should be stable to generate steady near-field light with proper energy density to heat the recording

In this work, we present a co-evolutionary genetic (CEGA) algorithm to adapt the optical launch powers and optimize the signal-to-noise ratio (SNR) values based on maximizing the minimum SNR margin. The introduced co-evolutionary algorithm provides lower computational complexity rather than convex optimization and linear programming techniques, applicable for both static and time-critical dynamic networking

The elastic optical network (EON) is the most attractive architecture for the next generation of optical networks. Dealing with high bit-rate traffic, EON faces the challenge of ensuring survivability to operate with stringent Service Level Agreements. This article proposes a Deep Neural Network model with a multi-objective Fuzzy Inference System (FIS) to solve the Routing and Spectrum Assignment problem

Increasing efficiency and productivity in the field of agriculture is important to provide sufficient food to the world’s increasing population. It is important to monitor crops using image processing in order to realize these increases in efficiency and productivity. In order to monitor crops with high quality and accuracy, high resolution images are needed. In this research, a crop monitoring method

We propose a field of view (FOV) enlargement method using the line symmetric image input in the single layer volumetric holographic waveguide. We build a mathematical model and analyze the virtual image to be seen by the observer considering the interaction volume of the signal light ray within the volumetric hologram waveguide. It is found that the diffracted light intensity is varied with each ray

We present the modeling of a porous core dispersion flatten photonic crystal fiber (PCF) for the fruitful transmission of THz signals. The model comprises only rectangular holes in both core and cladding areas. The model is numerically studied through simulation employing the finite element method (FEM)-based software. Simulation results disclose an insignificant amount of confinement loss (CL) of

A waveguide grating on a transparent substrate can serve as an optical notch filter owing to guided-mode resonance. The filtering wavelength is highly sensitive to an incidence angle. Potential of a two-dimensional grating for an application to three-dimensional angle-fluctuation sensing was investigated. Spectral variations due to the angle fluctuations were theoretically discussed and simulated using

To increase the recording density of optical discs, analog recording techniques such as the use of orthogonal frequency division multiplexing (OFDM) method has been investigated. In OFDM method, the recording signal is separated into several sub frequency bands. So the readout channel becomes tolerant of the deterioration by disturbances such as defocus and disc skew in optical disc systems. Faster

The application of a burst imaging method to digital holography (DH) with multiple image capturing is firstly demonstrated. Nobody has discussed this approach explicitly, although the burst imaging method is not so uncommon. The burst imaging method intermittently captures several images with a high repetition rate followed by a relatively long rest time. If the light wave from an object has a much

As an object is passing through a static scattering medium, a speckle is formed. We can reconstruct the image from the speckle, based on the principle of optical memory effect. However, when the object passes through a dynamic scattering medium, such as fog, the reconstructed image quality will be degraded even blurred. In this paper, we want to investigate the reconstructed image as the object passes

Space-division multiplexing (SDM) is regarded as one of the most promising technologies to satisfy the explosively growing internet traffic. Elastic optical networks with SDM is one of the newest network architectures for network planning in the future. However, the resource allocation problem in these networks becomes more complicated due to the expansion of spatial dimensions. In this paper, we propose

Nodes in a body area network (BAN) are miniature wearable or implantable battery-powered wireless sensors which continuously transmit real-time vital physiological data of a patient to remote health-care center while remaining in close proximity to the human body. Therefore, BAN nodes should have the features of high data rates and low transmit powers to protect the human body, environment and bio-medical

When a monochromatic electromagnetic plane-wave arrives at the flat interface between its transparent host (i.e., the incidence medium) and an amplifying (or gainy) second medium, the incident beam splits into a reflected wave and a transmitted wave. In general, there is a sign ambiguity in connection with the \(k\)-vector of the transmitted beam, which requires at the outset that one decide whether

The bidirectional reflectance distribution function (BRDF) that describes an angle-resolved distribution of surface reflectance is available for characterizing surface properties of a material. A one-shot BRDF imaging system can capture an in-plane color mapping of light direction extracted from a surface BRDF distribution. A surface roughness identification method is then proposed here using the imaging

The interdependence between communication networks, e.g., an optical backbone network, and power grids is a critical issue to take into account when designing and operating both systems. In fact, failures in one network may cause further failures in the other network and vice versa. This is because nodes in power grids (i.e., power generators, loads or interchange nodes) are controlled and managed

The Internet is a collection of interconnected Autonomous Systems (ASes) that use the Border Gateway Protocol (BGP) to exchange reachability information. In this regard, BGP stability and scalability in the inter-domain scope have been matters of major concern for many years, and network engineers have been applying several techniques to cope with these issues. BGP is also used intra-domain (internal

The correlation between electrical properties and surface plasmon resonance (SPR) wavelength was discussed using ITO grating coupler. ITO films were prepared on SiO\(_{2}\)/Si substrate by RF sputtering with thermal annealing, and the grating was directly fabricated on the sample surface by focused ion beam. Electron density and mobility were evaluated by fitting optical reflection spectra according

In Elastic Optical Networks (EONs), the way different service demands are supported in the network is ruled by the Routing, Modulation and Spectrum Assignment (RMSA) algorithm, which decides how the spectrum resources of the optical network are assigned to each service demand. In a dynamic EON, demand requests arrive randomly one at a time and the accepted demands last in the network for a random time

We developed a modulation code using a complex amplitude and established a method to demodulate the code based on a convolutional neural network (CNN) for holographic data storage. The developed 20:9 modulation code consists of nine symbols, each of which contains 4 bits of data representing the symbol position on which the complex amplitude is superimposed and 16 bits of data representing the actual

A computer-generated moiré profilometry based on flat image demodulation is proposed. A sinusoidal fringe pattern and its background light are modulated by two-frequency carrier fringes, respectively, to combine a composite grating. While this composite grating is projected onto the measured object, the composite deformed pattern can be captured by CCD camera. So the sinusoidal deformed pattern and

We propose colors light detection and ranging (LiDAR) using visible laser diodes (LD) of red, green, and blue (RGB) colors to identify colors as well as obtain position information of surrounding objects. To verify the principle, we performed round-trip time-of-flight (TOF) measurements by irradiating a target of different colors with pulsed light from a LD of RGB colors. It is clarified that accurate

A plasmonic planar lens operating at terahertz (THz) region based on InSb micro-slit array with varying dielectric slit width is designed and numerically investigated. Dielectric slits provide desired phase retardations of beam manipulating with varying phase propagation constant. Taking advantage of the permittivity thermo-tunable property of InSb, the focal spot of this lens can be actively controlled

A measurement system based on the Scheimpflug principle is designed in this paper to solve the problem of difficulty in clear imaging due to excessively small depth of field in line-structured light close-range photogrammetry. A conversion model from the image coordinate system to the measured object coordinate system is established through the spatial projection relationship. The calibration method

In Software-Defined Networking (SDN), the control and data planes are decoupled, leading to a more programmable and efficient network management. In this paper, the controller placement problem in SDN is addressed, jointly with the problem of exploring a high-availability tree subgraph, in order to support delay and availability requirements between the switches and the controllers. We consider that

The response of light in a nonlinear dispersive medium is governed by the nonlinear Schrödinger equation (NLSE). In general, for higher order group velocity dispersion (GVD) with frequency-dependent gain or absorption, NLSE is numerically solved using the split-step Fourier method. Extended NLSEs including the effects of higher order GVD, frequency-dependent gain and frequency-dependent absorption

We have previously presented a blood perfusion parameter by means of the spatial contrast of speckle patterns observed for blood perfusion in skin tissue and a blood vessel. This parameter permits us to visualize a relative blood perfusion distribution from a single speckle pattern. Therefore, it can estimate the blood perfusion with a frame rate of an imaging device employed. This parameter is, however

We propose a layout estimation method for multi-layered ink using a measurement of the line spread function (LSF) and machine learning. The three-dimensional printing market for general consumers focuses on the reproduction of realistic appearance. In particular, for the reproduction of human skin, it is important to control translucency by adopting a multilayer structure. Traditionally, layer design

To reduce the effect of atmospheric turbulence and stabilize the optical link in free-space optical (FSO) communications, we have proposed to use an optical duplicate system (ODS) as a multi-beam generator. In this paper, a transmitter adopting the ODS is designed and constructed for the experiment. Moreover, the experiment is conducted to transmit multi-beam generated by the ODS between two points

Polarization is useful for estimating surface normals. In this paper, polarization is applied to shape estimation. Surface normal estimation from a single image is commonly performed by shape-from-shading. An alternative approach is shape-from-polarization, which usually cannot uniquely determine the surface normal and must be accompanied by additional information. The shading information is a promising

Based on a Nd:LaMgAl11O19 (Nd:LMA) disordered crystal, we have experimentally demonstrated a diode-pumped high-repetition-rate Q-switched laser, which can operate at 1056, 1083 nm, or 1056 and 1083 nm, respectively, using a SF6 prism to adjust the cavity loss. For the three states, the characteristics of the Nd:LMA laser including the average output power, pulse width and frequency repetition rate

Remote visual testing by video cameras is the standard process for inspecting the pressure vessel of nuclear reactors. The inspectors need to find stress corrosion cracking of around several tens of µm wide on a display monitor observed by remote wired cameras in the reactor pressure vessel filled with cooling water. The inside surface of the vessel structure has typically been blasted or grinded during

We demonstrate a single-shot uniaxial 3D profilometry system that illuminates a sample with a structured polarization pattern and measures the reflected full-Stokes polarimetric image. Some non-contact 3D measurements require evaluating samples located in a protected environment. For example, this may be a sample under the lid of an acrylic Petri dish, a sample that has a protective film overlay, or

In this study, a simple hollow core hexagonal structured photonic crystal fiber is offered and analyzed to discern commonly used different type of alcohols in our daily life. The proposed sensor guiding properties are numerically investigated using a full vectorial finite element software-based scheme. To ensure higher accuracy, the properties of alcohols (refractive index and dielectric constant)

In this paper, we propose the design of a survivable energy-efficient and crosstalk-aware routing, spectrum, and core allocation (RSCA) scheme for online multiclass traffic in both spectral and temporal domains in SDM-EON. Multipath based protection scheme is applied to ensure survivability against single link failure. Advanced reservation (AR) connections being a part of multiclass traffic may withstand

We propose, and experimentally demonstrate, an SDN (Software Defined Networking) new management solution for legacy GPONs (Gigabit Passive Optical Networks), which allows users to dynamically control their residential networks by means of a management application. In this way, users can customize the allocation of resources (and set constraints, if desired) to connected devices in their residential

In this letter, the high-order harmonic generation (HHG) of wurtzitic and hexagonal boron nitride (h-BN) under ultrafast intense laser field was studied by solving an extended multiband semiconductor Bloch equations (SBEs). The results showed that for both the wurtzitic and hexagonal structures, the cutoff energy of the HHG was extended linearly by increasing the field strength, and the efficiency

Based on the probability density function of the composite channel considering Malaga atmospheric turbulence, pointing error and atmospheric path loss, the asymptotic expressions of channel capacity and outage probability for binary phase shift keying (BPSK) modulation system are derived using Meijer G function. The numerical results show that under the same intensity of turbulence and path loss condition

Orbital angular momentum (OAM) beams have orthogonality between them, which can greatly increase the capacity of a communication system, but an OAM multiplexed communication system will be affected by atmospheric turbulence during transmission, which will cause channel crosstalks. In this paper, we adopt the blind equalization algorithm, which can recover multiple signals with blinding source separation

We have provided two compact designs of on-chip silicon photonic crystal (PhC) AND and XOR logic devices, which can provide multiple logic functions through different input frequencies within one structure. Compared to the former ones, the overall size is short to 10a × 18a (approximately 4 × 8 μm2). The working principle of the structures is lead to the directional leakage of the center cavity and