Optical Waveguide Transmission Research Articles

Crystal Engineering-Driven Sunlight Responsiveness and Flexible Waveguide Transmission.

Here, a barbituric acid derivative containing pyrene rings (DPPT) was successfully synthesized, and two types of crystals were prepared by using crystal engineering methods. Orange sheet-like crystals (DPPT-O, observed in visible light), prepared in a DCM/CH3OH solution, exhibited brittleness and weak fluorescence emission, along with sunlight-induced bending and fracturing. Red needle-like crystals (DPPT-R, also observed in visible light), synthesized in a DCM/CH3CN solution, demonstrated elastic properties, strong fluorescence emission, and excellent optical waveguide performance (with an optical loss coefficient of 0.23-0.30 dB mm-1). Single-crystal data analysis revealed that the stacking arrangement of molecules critically influenced the elasticity of the crystals, while the reaction cavity size regulated the photomechanical properties of the crystals. This study achieved effective control over sunlight responsiveness and flexible optical waveguide transmission for the first time, providing innovative insights for the application of homogeneous organic polycrystalline molecular crystals in this field.

Highly controllable stabilization and switching of multiple colliding soliton sequences with generic Ginzburg–Landau gain–loss

We investigate propagation of J soliton sequences in a nonlinear optical waveguide array with generic weak Ginzburg–Landau (GL) gain–loss and nearest-neighbor (NN) interaction. The propagation is described by a system of J perturbed coupled nonlinear Schrödinger (NLS) equations. The NN interaction property leads to the elimination of collisional three-pulse interaction effects, which prevented the observation of stable multisequence soliton propagation with J>2 sequences in the presence of generic GL gain–loss in all previous studies. We show that the dynamics of soliton amplitudes can be described by a generalized J-dimensional Lotka–Volterra (LV) model. Stability and bifurcation analysis for the equilibrium points of the LV model, which is augmented by an application of the Lyapunov function method, is used to develop setups that lead to robust and scalable transmission stabilization and switching for a general J value. The predictions of the LV model are confirmed by extensive numerical simulations with the perturbed coupled-NLS model with J=3, 4, and 5 soliton sequences. Furthermore, soliton stability and the agreement between the LV model’s predictions and the simulations are not reduced with increasing value of J. Therefore, our study provides the first demonstration of robust control of multiple colliding sequences of NLS solitons in the presence of generic weak GL gain–loss with an arbitrary number of sequences. Due to the robustness and scalability of the results, they can have important applications in stabilization and switching of broadband soliton-based optical waveguide transmission.

Low-Cost Distributed Optical Waveguide Shape Sensor Based on WTDM Applied in Bionics.

Bionic robotics, driven by advancements in artificial intelligence, new materials, and manufacturing technologies, is attracting significant attention from research and industry communities seeking breakthroughs. One of the key technologies for achieving a breakthrough in robotics is flexible sensors. This paper presents a novel approach based on wavelength and time division multiplexing (WTDM) for distributed optical waveguide shape sensing. Structurally designed optical waveguides based on color filter blocks validate the proposed approach through a cost-effective experimental setup. During data collection, it combines optical waveguide transmission loss and the way of controlling the color and intensity of the light source and detecting color and intensity variations for modeling. An artificial neural network is employed to model and demodulate a data-driven optical waveguide shape sensor. As a result, the correlation coefficient between the predicted and real bending angles reaches 0.9134 within 100 s. To show the parsing performance of the model more intuitively, a confidence accuracy curve is introduced to describe the accuracy of the data-driven model at last.

Properties of a novel hybrid hollow core photonic crystal fiber

Abstract We present a novel hybrid hollow-core photonic crystal fiber, which can confine and guide light in subwavelength-diameter air holes of core. The propagation mechanism of low-refractive-index hole is studied by evanescent field coupling and electromagnetic theory of optical waveguide transmission. The unique transmission characteristics in the novel fiber with new propagation mechanism are shown. The evanescent-field power fraction in the core holes can be changed flexibly between 10% and 50%. The confinement loss is very low in the broadband wavelength range 1–1.8 μm, which is not limited by surface modes and photonic bandgap effect appearing in hollow-core photonic bandgap fibers. The excellent characteristics of matching mode area, high birefringence, single polarization and single mode in hollow-core fiber are obtained. The two-zero dispersion, broadband flattened dispersion and dispersion compensation properties of hollow-core fiber are also presented. The novel hybrid photonic crystal fiber has the characteristics of solid core fibers and is suitable for the application as hollow core fibers.

Multi-Physics Modeling and Simulation of Electro-Optical Sensing

With the rapid development of UHV technology, Electric field measurement technique has attracted lots of people's attention.Electro-optical sensors for measuring the electric field to become the main method due to the crystal optical fiber preparation and mature technology. This article describes the basic principles that Mach - Zehnder of lithium niobate optical modulator for electric field measurements.Designing the Mach - Zehnder electro-optic sensors in the Comsol Multiphysics oftware, the calculation model for the simulation results of bending radius that the optical waveguide transmission power loss minimum, a 3dB directional coupler to determine the length of the arm and finally adding a signal voltage, the applied voltage is obtained a linear relationship between the output power.

Planar optical waveguides for civil and military applications

There is significant military and civil interest in being able to detect chemical species adsorbed from air or present in aqueous solutions. Planar optical waveguide transmission properties are sensitive to changes in parameters such as refractive index or absorption and to light-emitting processes such as fluorescence. These changes modulate light travelling in optical waveguides, and so may be used as sensors for detecting biological and chemical agents, non-ionizing and ionizing electromagnetic radiation. Several waveguide systems have been studied theoretically and experimentally, and their responses to basic influences such as alcohol and UV radiation, and gamma rays determined.

Solar Thermal Power for Lunar Materials Processing

Lunar in situ resource utilization (ISRU) processes require thermal energy at various temperatures. Chemical recovery processes (pyrolysis, gas-solid reactions, gas-liquid or three-phase reactions and desorption) require thermal energy at temperatures from 1,000 K to 2,500 K . Manufacturing processes (hot liquid processing, sinter forming, composite forming, welding, etc.) can be accomplished with thermal energy at temperatures 1,200 K–1,800 K . For these materials, process applications or solar thermal power can be effectively utilized. Physical Sciences Inc. has been developing an innovative solar power system in which solar radiation is collected by the concentrator, which transfers the concentrated solar radiation to the optical waveguide transmission line made of low loss optical fiber. In this paper, we will review our work on the development of the solar thermal power system and its application to a lunar ISRU process.

Analysis and Application of the Transmission Spectrum of a Composite Optical Waveguide

A composite optical waveguide (OWG) was fabricated by use of the masked sputtering method to deposit a tapered TiO2 film onto a single-mode potassium ion-exchanged (PIE) planar waveguide. Using the slab OWG spectroscopy apparatus, including a xenon lamp and a charge-coupled device (CCD) spectrometer, transmission spectra of the composite OWG with different superstrates were measured in the wavelength range 400 to 900 nm. The findings show that the composite OWG transmission spectrum is sensitive to the refractive index of the liquid overlaid on the TiO2 film. The sensing mechanism is considered to be the liquid-index-induced change in surface-scattering loss for the guided mode coupled adiabatically from the PIE layer into the TiO2 film. The composite OWG transmission spectrum and its response to liquid index exhibit strong polarization dependence due to large differences in properties between the TE0 and TM0 modes in the TiO2 film. The composite OWG transmission spectroscopy as a new refractometry was analyzed experimentally and theoretically.

Optimization and characterization of the guest-host polyetherketone polymer films for application in integrated optical devices

In order to optimize the loading of 3-(1,1-dicyanothenyl)-1-phenyl-4, 5-dihydro-1H-pryazole (DCNP) in polyetherketone (PEK-c) guest-host polymer films, ten kinds of DCNP/PEK-c thin films, in which the weight per cent of DCNP changes from 5 to 50, were prepared. Their second-order nonlinear optical coefficients χ33(2) at λ = 1064 nm were measured by using Maker fringe method after poling under the optimal poling condition. Their optical waveguide transmission losses were measured at 632.8 nm. Optimal weight per cent of the chromophore for the DCNP/PEK-c guest-host polymer system has been determined as about 20 for use in the integrated optical devices.

Optical characterization of waveguide based photonic microstructures

Third-order, one-dimensional, semiconductor-air gratings have been designed, fabricated, and evaluated by optical waveguide transmission measurements. Gratings with as little as six unit cells show a clear band edge around 840–850 nm. Owing to our approach of semiconductor-rich lattices with small airgaps, the diffractive spreading loss is sufficiently small (∼50% in the passband) for meaningful results to be extracted. The measurements indicate that the optical waveguide approach is a good starting point for the study of photonic microstructures and that practical device concepts can be implemented.

Wannier-Stark localization in a 1.55 mu m InGaAs/InAlAs superlattice waveguide modulator structure

The authors present an optical waveguide modulator structure based on Wannier-Stark localization in a InGaAs-InAlAs superlattice. Optical waveguide transmission below the superlattice bandgap displays expected F/sup -1/ oscillatory behavior leading to various modulation schemes. An 11 dB extinction ratio was obtained by applying a 0.7 V drive voltage to a 100 mu m long waveguide device operating at 1.55 mu m under a transverse-electric (TE)-polarization mode. On-state attenuation was 5 dB. Lower open-state attenuation (3 dB) can be obtained simultaneously with a higher extinction ratio (13 dB) but in that case a larger drive voltage (1.6 V) is needed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Calculation of duobinary transmission systems with optical waveguides

A calculation and optimization method for optical waveguide transmission systems using the principle of digital duobinary transmission is presented. Then, systems with duobinary reception and systems with raised-cosine reception, which also need an equalizer at the receiving end, are compared with regard to the energy per single signal required for a tolerable bit error probability. Other criteria of comparison, such as susceptibility to jitter, additional duobinary system hardware, and error detection facilities, are considered, too. The results of the calculations show that in an optical waveguide transmission system where the duration of the signal at the optical waveguide output exceeds a defined value, the performance of the duobinary system is better than that of the raisedcosine system when the attainable repeater section lengths are compared.