45-cm long compression-molded polymer-based optical bus

Design, fabrication and characterization of a photodefinable benzocyclobutene (BCB 4022-35 is a product of DowTM) single mode rib optical waveguide is presented in this work. At first, the refractive index of polymer film is measured by the method of prism coupling. We design the single mode rib waveguide based on the geometrical adjustment of rib width, total waveguide height using conventional R-soft BPM and effective index methods. Based on the design results, BCB waveguides were fabricated by using photolithographic process with wet etching, which is quite complicated and time consuming. In this work, the insertion and propagation losses of waveguide are measured by using the conventional cut back method. The insertion losses of waveguide are 3.95 dB and 4.08 dB for TE and TM modes respectively. The propagation losses of waveguide are 1.09dB/cm and 1.20dB/cm for TE and TM modes respectively. 

Optical interconnections using two-dimensional waveguides are presented. Light beams whose incident angles are greater than the critical angle of a waveguide can propagate within that waveguide, which behaves as an optical bus. Such optical buses are suitable for massively parallel processing because they have a large number fan-outs and no skew. Estimated propagation distance in the waveguides is roughly 500 mm. One to several hundred interconnections may be achieved. Glass plates with concave lenses are used to demonstrate bus operations.

Performance of the effective index method in the modeling of nanoscale rectangular apertures in a real metal

Graphene is used as an ideal platform for plasmonic optical devices due to its unique electrical and optical characteristics. We proposed a unique effective index method to evaluate a graphene-based half Maxwell fish-eye (HMFE) plasmonic lens on a single flake of graphene, which can focus a surface plasmon polariton plane wave and transform into a spherical wave. Similar to traditional optics, the proposed method can be used to investigate the focusing performance of an HMFE lens versus different parameters, including the incident frequencies, the discrete semiring numbers, the chemical potentials, and the size of the proposed lens. In addition, we use two proposed lenses to build an optical-coupling element, which can transform the beam of a plane wave into a different beam width. The proposed effective index method can be used as a reference in designing plasmonic optical devices with a variable effective index profile on a flake of graphene. The finite element method is employed to realize the numerical simulation, which demonstrates results almost consistent with our design methodology.

An approximate method is here proposed for modelling two-dimensional sub-wavelength periodic structures. The method is based on the effective index method, where the two-dimensional problem structure is split on two one-dimensional problems, which can be solved by conventional tools. It provides in a natural way the biaxial character of a two-dimensional periodic structure with different period along different directions. The method has been tested by comparing the effective refractive index provided by more exact algorithms with the one provided by the effective index method, showing quite good agreement. Also, the EIM has been used to simulate the reflectance and transmittance behaviour of pyramidal profiles, showing also good agreement with the results supplied by exact calculations using RCWA technique. The main advantages of the method are that it is easy to implement, and the short computational time required to model a given structure.

In this paper, we apply the recently proposed effective- index method with built-in perturbation correction to the study of direcitonal coupler that consists of two parallel rectangular-core waveguides. We show with numerical examples that the splitting ratio of the directional coupler can be made insensitive to the polarization state of the input light by using proper waveguide parameters.

The effective index method for calculating waveguide mode dispersion is reviewed and applied to uniform rectangular optical waveguides with both small and large index differences. The results are shown to be at least as accurate as other approximate techniques. The effective index method is then applied to channel waveguides assuming 1-D and 2-D diffusion. Channel waveguides without sideways diffusion are shown to be described by the method using a normalized notation and previously published universal dispersion curves. Two-dimensional diffusion theory is applied to treat the case of isotropic sideways diffusion. A new, normalized, 1-D universal chart is obtained which in conjunction with previous results defines waveguide mode dispersion in isotropically diffused 2-D channels.

This work is aimed at implementation and practical verification of effective index approach applicability to microstructured fibers modeling. In particular, the Effective Index Method, both in scalar and fully vectorial form, is presented and discussed with respect of its potential applications for fast and accurate modeling of chromatic dispersion of index guiding microstructured fibers. The developed models, implemented in Matlab environment, allow visualization of the dispersion profiles of index guiding microstructured fibers with hexagonal lattice. To verify accuracy and define the applicability range of developed models, the results of modeling were confronted with the sparse experimental data, reported up to now in scientific papers. The satisfying agreement between numerical and measured results has been obtained, confirming the accuracy of developed model and its applicability to fast analysis and designing of microstructured fibers with dielectric core.

A type of monomode step-index channel guide is presented, such that modal propagation can be solved by the effective index method, in a quasi-exact form. With these results both the designing and fabrication of integrated optical devices based on channel guides, such as directional couplers, can be greatly simplified and improved.

Investigating photonic components as refractive index sensors requires reliable numerical models. Performing 3D simulations of large or complex components requires powerful hardware. Alternatives to time-consuming 3D simulations are approximations such as the effective refractive index method. We propose our improved method that more closely follows 3D results, named the inverse effective index method. The accuracy of our approximation method is verified by comparing experimental results with simulations. Ring resonators with 40μm radius are simulated and fabricated. Their qualities as refractive index sensors are assessed by probing their response in DI-water and in various saline solutions. The fabricated resonators are fitted with a microfluidic channel for sample delivery. A tunable laser is used to induce resonance in the ring resonators and the resonance frequencies are measured for all solutions. The accuracy between simulation and experimental data is found to rely heavily on the approximation technique being used. The differences vary from 300% to 6% depending on the approximation method. The fabrication and characterization of the ring resonator-based refractive index sensor took approximately two days, whereas the 2D simulations took under an hour to perform. This demonstrates the usefulness of a proper simulation tool to conduct accurate performance estimations in a short amount of time.

An effective index method is proposed for all-solid photonic bandgap fibres, where the effective cladding index is taken to be that of the lower edge of the bandgaps. The weak-guidance approximation allows the effective indices of both the fibre cladding and the defect modes to be calculated analytically. Comparison with a vectorial plane wave method shows that good accuracy is obtained.

“Effective index method“’ Is it valid for nano-circuitry based on plasmonic gaps?

The paper presents a numerical implementation of the Effective Index Method (EIM) for the determination of the propagation constants and field distributions in dielectric or semiconductor guiding structures that are uniform on the direction of propagation. The implementation proved to be applicable to a wide range of guiding structures (ridge, buried and diffused guides) and was tested against analytical solutions and against other methods' results proving good accuracy. The advantages and limitations of the EIM are discussed and a common waveguide problem result is presented as an example. From the practical applications of the method, the optical analysis of the ridge geometry and QW positioning of a 3W continuous wave GRIN SCH SQW laser diode in the 670 nm band is briefly discussed and the measured performances of the devices are presented.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper, an extension of the effective index method (EIM) to waveguiding structures containing ideal or saturable third-order nonlinear materials is presented. By applying separation of variables to the dominant field component, the complete problem is subdivided into two scalar problems in the lateral and transverse direction, as in the case of the normal EIM. Making use of the strong transverse confinement, as observed in most real waveguide structures, the nonlinear index changes of the various transverse sections can be lumped into nonlinear effective indexes of the equivalent layered planar structures. By using these nonlinear effective indexes in self-consistent field calculations in the transverse direction, a complete approximate solution is obtained. In this way, the amount of computational effort required for the calculation of the effective indexes and field profiles of the waveguides can be reduced significantly.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An external DC magnetic field may change the dispersion diagram of periodic structures, so that tunable reciprocal and non-reciprocal plamonic components may be constructed. In this study, the effect of an external DC magnetic field on the dispersion diagram of plasmonic periodic structures will be investigated by the effective refractive index method. Investigations are focused on the Voigt and Faraday configurations, although it can be extended to other configurations. In this regard, the wave equation for both structures is solved, eigenpropagation constants and eigenpolarisation are derived. Then, the effective propagation constant and finally, the dispersion diagram for the Voigt and Faraday structures will be derived. The effect of the bias field is investigated on the aforementioned structures. It is seen that tunable periodic structures can be achieved by the magnetoplasmonic configurations. Different dispersion diagrams can be obtained for different modal waves. For both structures, there is a transmission band for frequencies below the plasma frequency, especially for extremely low frequencies, where in the absence of a magnetic field, wave transmission is impossible. There is no limit on the period of structure, the period of structure in the simulation varies from zero to 1.6λp.