Influence of Waveguide Properties on Wave Prototypes Likely to Accompany the Dynamics of Four-Wave Mixing in Optical Fibers

In this article, we study the impacts of nonlinearity and dispersion on signals likely to propagate in the context of the dynamics of four-wave mixing. Thus, we use an indirect resolution technique based on the use of the iB-function to first decouple the nonlinear partial differential equations that govern the propagation dynamics in this case, and subsequently solve them to propose some prototype solutions. These analytical solutions have been obtained;we check the impact of nonlinearity and dispersion. The interest of this work lies not only in the resolution of the partial differential equations that govern the dynamics of wave propagation in this case since these equations not at all easy to integrate analytically and their analytical solutions are very rare, in other words, we propose analytically the solutions of the nonlinear coupled partial differential equations which govern the dynamics of four-wave mixing in optical fibers. Beyond the physical interest of this work, there is also an appreciable mathematical interest.

Waveguide-integrated optical modulators with two-dimensional materials

Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing.To cope with the ever-increasing amount of data being generated and consumed,ultrafast waveguide-integrated optical modulators with low energy consumption are highly demanded.In recent years,two-dimensional(2D)materials have attracted a lot of attention and have provided tremendous opportunities for the development of high-performance waveguide-integrated optical modulators because of their extraordinary optoelectronic properties and versatile compatibility.This paper reviews the state-of-the-art waveguide-integrated optical modulators with 2D materials,providing researchers with the developing trends in the field and allowing them to identify existing challenges and promising potential solutions.First,the concept and fundamental mechanisms of optical modulation with 2D materials are summarized.Second,a review of waveguide-integrated optical modulators employing electro-optic,all-optic,and thermo-optic effects is provided.Finally,the challenges and perspectives of waveguide-integrated modulators with 2D materials are discussed.

Optical microwave generation using two parallel DFB lasers integrated with Y-branch waveguide coupler

A new device of two parallel distributed feedback （DFB） lasers integrated monolithically with Y-branch waveguide coupler was fabricated by means of quantum well intermixing. Optical microwave signal was generated in the Y-branch waveguide coupler through frequency beating of the two laser modes coming from two DFB laser in parallel, which had a small difference in frequency. Continuous rapid tuning of optical microwave signal from 13 to 42 GHz were realized by adjusting independently the driving currents injected into the two DFB lasers.

Single-photon scattering and quantum entanglement of two giant atoms with azimuthal angle differences in a waveguide system

We theoretically investigate coherent scattering of single photons and quantum entanglement of two giant atoms with azimuthal angle differences in a waveguide system.Using the real-space Hamiltonian,analytical expressions are derived for the transport spectra scattered by these two giant atoms with four azimuthal angles.Fano-like resonance can be exhibited in the scattering spectra by adjusting the azimuthal angle difference.High concurrence of the entangled state for two atoms can be implemented in a wide angle-difference range,and the entanglement of the atomic states can be switched on/off by modulating the additional azimuthal angle differences from the giant atoms.This suggests a novel handle to effectively control the single-photon scattering and quantum entanglement.

Waveguide Bragg Grating for Fault Localization in PON

Femtosecond laser direct inscription is a technique especially useful for prototyping purposes due to its distinctive advantages such as high fabrication accuracy,true 3D processing flexibility,and no need for mold or photomask.In this paper,we demonstrate the design and fabrication of a planar lightwave circuit(PLC)power splitter encoded with waveguide Bragg gratings(WBG)using a femtosecond laser inscription technique for passive optical network(PON)fault localization application.Both the reflected wavelengths and intervals of WBGs can be conveniently tuned.In the experiment,we succeeded in directly inscribing WBGs in 1×4 PLC splitter chips with a wavelength interval of about 4 nm and an adjustable reflectivity of up to 70% in the C-band.The proposed method is suitable for the prototyping of a PLC splitter encoded with WBG for PON fault localization applications.

Cyclodextrin Polymer Films Optical Waveguide Sensor for Volatile Organic Gas Detection

A sensitive optical waveguide（OWG） sensor which can be used to detect volatile organic compounds（VOCs） was presented.The sensing device（element） was fabricated by means of the immobilization of polyvinyl pyrrolidone（PVP）-cyclodextrin（CD） composite film over a single-mode potassium ion exchanged glass OWG via spin-coating method.The sensor shows higher response to styrene gas than to other VOCs and displays a linear response to styrene gas in a range of 1―1000 μL/L.

Femtosecond laser direct writing of flexibly configured waveguide geometries in optical crystals:fabrication and application

Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established based on crystalline materials,particularly,are opening exciting possibilities and opportunities in photonic chips by facilitating their on-chip integration with different functionalities and highly compact photonic circuits.Femtosecond-laser-direct writing(FsLDW),as a true three-dimensional(3D)micromachining and microfabrication technology,allows rapid prototyping of on-demand waveguide geometries inside transparent materials via localized material modification.The success of FsLDW lies not only in its unsurpassed aptitude for realizing 3D devices but also in its remarkable material-independence that enables cross-platform solutions.This review emphasizes FsLDW fabrication of waveguide structures with 3D layouts in dielectric crystals.Their functionalities as passive and active photonic devices are also demonstrated and discussed.

Multifunctional flexible optical waveguide sensor: on the bioinspiration for ultrasensitive sensors development

This paper presents the development of a bioinspired multifunctional flexible optical sensor(BioMFOS)as an ultrasensitive tool for force(intensity and location)and orientation sensing.The sensor structure is bioinspired in orb webs,which are multifunctional devices for prey capturing and vibration transmission.The multifunctional feature of the structure is achieved by using transparent resins that present both mechanical and optical properties for structural integrity and strain/deflection transmission as well as the optical signal transmission properties with core/cladding configuration of a waveguide.In this case,photocurable and polydimethylsiloxane(PDMS)resins are used for the core and cladding,respectively.The optical transmission,tensile tests,and dynamic mechanical analysis are performed in the resins and show the possibility of light transmission at the visible wavelength range in conjunction with high flexibility and a dynamic range up to 150 Hz,suitable for wearable applications.The BioMFOS has small dimensions(around 2 cm)and lightweight(0.8 g),making it suitable for wearable application and clothing integration.Characterization tests are performed in the structure by means of applying forces at different locations of the structure.The results show an ultra-high sensitivity and resolution,where forces in theμN range can be detected and the location of the applied force can also be detected with a sub-millimeter spatial resolution.Then,the BioMFOS is tested on the orientation detection in 3D plane,where a correlation coefficient higher than 0.9 is obtained when compared with a gold-standard inertial measurement unit(IMU).Furthermore,the device also shows its capabilities on the movement analysis and classification in two protocols:finger position detection(with the BioMFOS positioned on the top of the hand)and trunk orientation assessment(with the sensor integrated on the clothing).In both cases,the sensor is able of classifying the movement,especially when analyzed in conjunction with preprocessing and clustering techniques.As another wearable application,the respiratory rate is successfully estimated with the BioMFOS integrated into the clothing.Thus,the proposed multifunctional device opens new avenues for novel bioinspired photonic devices and can be used in many applications of biomedical,biomechanics,and micro/nanotechnology.

Extraordinary transmission and reflection in PT-symmetric two-segment-connected triangular optical waveguide networks with perfect and broken integer waveguide length ratios

By adjusting the waveguide length ratio, we study the extraordinary characteristics of electromagnetic waves propagating in one-dimensional(1D) parity-time-symmetric(PT-symmetric) two-segment-connected triangular optical waveguide networks with perfect and broken integer waveguide length ratios respectively. It is found that the number and the corresponding frequencies of the extremum spontaneous PT-symmetric breaking points are dependent on the waveguide length ratio. Near the extremum breaking points, ultrastrong extraordinary transmissions are created and the maximal can arrive at, respectively, 2.4079 × 10^14 and 4.3555 × 10^13 in both kinds of networks. However, bidirectional invisibility can only be produced by the networks with broken integer waveguide length ratio, whose mechanism is explained in detail from the perspective of photonic band structure. The findings of this work can be useful optical characteristic control in the fabrication of PT-symmetric optical waveguide networks, which possesses great potential in designing optical amplifiers,optical energy saver devices, and special optical filters.

10 Gb/s Optical Interconnection on Flexible Optical Waveguide in Electronic Printed Circuit Board

In this paper, we proposed 10 Gb/s transmission using 4-channel polymer waveguides on the optical electronic printed circuit board. It was simulated by the ray tracing method for tolerance study of optical interconnection and fabrication. In order for easy fabrication and high position accuracy, the polymer waveguides were forming silver coated 45° reflective mirrors by dicing method and e-beam deposition for 90° light beam turning. The coupling loss was demonstrated in different polishing grit sizes. The optical interconnection in board-embed 4-channel flexible waveguides was demonstrated with a low propagation loss of 0.1 dB/cm and a clear eye diagram at 2.5 Gb/s data rate per channel.

Automated visual position detection and adjustment for optical waveguide chips and optical fiber arrays

The alignment coupling between optical waveguide chips and optical fiber arrays is the basis of the alignment coupling of planar optical waveguide devices, and the precise position detection with angle and spacing adjustments is one of the key steps of alignment coupling. A methodology for position detection, and angle and spacing adjustment was proposed for optical waveguide chips and optical fiber arrays based on machine vision. The experimental results show angle detection precision levels higher than 0.05°, line detection precision levels higher than 0.1 μm, and detection time less than 2 s. Therefore, the system developed herein meets the precise requirements necessary for position detection, and angle and spacing adjustments for optical waveguide chips and optical fiber arrays.

Research and Design of Ge_(0.6)Si_(0.4)/Si Strained-layer Superlattice Planar Optical Waveguide

Calculation shows that the refraction index of Ge 0.6 Si 0.4 /Si strained layer superlattice n ≈3.64, when L w=9 nm and L b=24 nm. An algorithm of numerical iteration for effective refraction index is employed to obtain different effective refraction indexes at different thickness ( L ). As a result, the thickness of Ge 0.6 Si 0.4 /Si strained layer superlattice optical waveguide, L ≤363 nm, can be determined, which is very important for designing waveguide devices. An optical waveguide can be made into a nanometer device by using Ge 0.6 Si 0.4 /Si strained layer superlattice.

A New Type of Fiber-induced Optically Controllable Silicon-loaded Millimeter Waveguide Switch

In this paper,a new type of optically controllable silicon slab loaded E-plane millimeterwave rectangular waveguide switch is presented.It uses SELFOC lens to couple optical puls-es to silicon slab with optical fiber.The on/off ratio reaches 42dB,the front fringe of suchkind swith is less than 0.05μs,and the insertion loss is less than 1dB in the full band of 26.5GHz to 40GHz.

Optical soliton with group delay in microring coupled-resonator optical waveguides

This paper derives the dispersion relation of microring coupled-resonator optical waveguides （CROWs） without any approximation by using the transfer matrix method. Based on the established dispersion relation of CROWs it obtains the slow group velocity and dispersion coefficient. It finds that the effect Of dispersion on optical pulses can be adjusted to balance the effect of nonlinearity by changing coupling coefficient or loss, so optical soliton with group delay can be obtained in microring CROWs. The optical soliton with group delay is of great significance for applications of microring CROWs in delay lines and optical buffers of future all-optical communication systems.

A SIMPLE SOLUTION FOR MULTILAYER METALLIC OPTICAL WAVEGUIDES

A simple solution for a multilayer metallic optical waveguide by transforming it intoan equivalent three-layer slab waveguide is presented. The dispersion relation of the equivalentthree-layer slab waveguide is solved by using a simple iterative formula. This method itself isexact and can approach any accuracy desired. Moreover, the numerical results for four-layer andfive-layer structures show that the second-order solution is also accurate enough. It is simple andhas the same form of expressions for TE and TM modes and for different layer structures.

Mode-field half-widths of Gaussian approximation for the fundamental mode of two kinds of optical waveguides

This paper analyzes the characteristic of matching efficiency between the fundamental mode of two kinds of optical waveguides and its Gaussian approximate field.Then, it presents a new method where the mode-field half-width of Caussian approximation for the fundamental mode should be defined according to the maximal matching efficiency method. The relationship between the mode-field half-width of the Gaussian approximate field obtained from the maximal matching efficiency and normalized frequency is studied; furthermore, two formulas of mode-field half-widths as a function of normalized frequency are proposed.

FLUORINATED PHTHALAZINONE-CONTAINING COPOLYIMIDES FOR PASSIVE OPTICAL WAVEGUIDES

A series of fluorinated copolyimides containing phthalazinone moieties were prepared from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride(6FDA),3,3'4,4'-benzophenone-tetracarboxylic dianhydride(BPDA)and2-(4-aminophenyl)-4-[4-(4-aminophenoxyl)phenyl]-2,3-phthalazin-1-one(DHPZ-2NH_2)for making polymeric opticalwaveguides.The resulting copolymers containing 0-50 mo1% BPDA/DHPZ-2NH_2 show good solubility and are soluble insome organic polar aprotic solvents.The copolyimides also present excellent thermal stability.These polymers possess highglass transition temperature higher than 603 K and high decomposition temperature above 742 K determined by differentialscanning calorimetry and thennogravimetric analysis,respectively,under a nitrogen atmosphere.Their refractive indicescould be controlled by varying the ratio of 6FDA and BPDA in the copolymer from 0.5 to 1.0,and the in-plane refractiveindices(n_(TE))range from 1.6366 to 1.6668 and the out-of-plane refractive indices(n_(TM))from 1.6024 to 1.6280 at 632.8 nm.The polymers birefringence(0.0342-0.0388)is almost independent of the 6FDA content of copolymer,which indicated thatthe phthalazinone-containing copolyimides could be suitable to fabricate optical waveguides possessing a low polarizationdependent loss(PDL).

A MATRIX METHOD FOR SOLVING PLANAR DIELECTRIC OPTICAL WAVEGUIDES

A matrix method used in multilayer stack of dielectric films is applied-to planar dielectric optical waveguides. A simple and applicable method for obtaining characteristic equation is presented.

Optical Waveguide and Nonlinear Properties of Bi_3NdTi_3O_(12) Thin Films

Neodymium-substituted bismuth titanate （Bi3NdTi3O12, BNT） thin films were prepared on quartz substrates by a metal-organic solution deposition process. The crystalline structure was evaluated by X-ray diffraction. Waveguide property was investigated by using prism coupling technique and optical transmittance measurement. The optical nonlinearities of the film were measured by the top-hat Z-scan techniques and a large positive nonlinear refractive index, nonlinear refractive coefficient and two-photon absorption coefficient were determined to be 3.84×10^7 esu, 0.7523 cm^2/GW and 4.81×10^4 cm/GW, respectively. These results reveal that the BNT film may be a kind of new multifunctional materials.

CALCULATION OF INFRARED OPTICAL CONSTANTS FOR CO_2 LASER HOLLOW WAVEGUIDE MATERIALS

A simple method was deduced for calculat-ing optical constant, optical loss and transmittance per meter of hollow-core optical fiber using data analysis method, ge-ometerical optical and electromagnetic theory. The method was used to study the Na2O-ZnO-GeO2-SiO2-PbO and Sb2O3 sysem. The glasses have nr<1 region. When the core diameter ao is 0. 5mm, the hollow waveguides of the Sb2O3-containing . glass is predicted with minimum loss of 0. 8 dB/m at 940cm-1