A method for the characterisation of the process-induced optical loss in butt-coupled passive waveguides will be described. In principle the results are valid for any active-passive waveguide butt-coupling as well (e....
详细信息
A method for the characterisation of the process-induced optical loss in butt-coupled passive waveguides will be described. In principle the results are valid for any active-passive waveguide butt-coupling as well (e.g. laser-waveguide). The method was applied to butt-coupled waveguides, which were grown by selective area metal organic vapour phase epitaxy (MOVPE). Different etching procedures for the preparation of the masked mesa stripes were examined, which considerably influenced the regrowth behaviour close to the mesa edge. The optical loss at the interface was found to depend primarily on the thickness difference of the waveguides. The excess layer thickness due the regrowth near the mesa is proportional to the width of the masked stripe. It reaches a factor of 1.7 at 50 mu m wide stripes and decreases exponentially with distance from the stripe (1/e length = 26 mu m). In general the measured loss values agree with the numerical simulation at least for stripe widths greater than or equal to 30 mu m. For stripe widths of less than or equal to 30 mu m loss values I 1 dB have been obtained in all cases, but deviations of the calculated loss values occurred, which can be attributed to the regrowth geometry at the interface.
We present experimental results and a theoretical analysis of remote switching and coupling of light in structures with two and three hollow-core AntiResonant Reflecting Optical waveguide (ARROW) layers. For the analy...
详细信息
We present experimental results and a theoretical analysis of remote switching and coupling of light in structures with two and three hollow-core AntiResonant Reflecting Optical waveguide (ARROW) layers. For the analysis, we have developed a numerical method based on the propagation of rays in the coupling structure and their coherent addition at the interfaces.
A simplified model is developed for the determination of the dispersion diagram and modal fields in rectangular corrugated waveguides with corner filled corruptions. The model, although relying on numerical methods, p...
详细信息
A simplified model is developed for the determination of the dispersion diagram and modal fields in rectangular corrugated waveguides with corner filled corruptions. The model, although relying on numerical methods, provides a computationally efficient technique. Theoretical results show a good agreement with experiments.
The necessity of using effective absorbing boundary conditions (ABCs) to terminate microstrip or other planar waveguides in the FDTD method has long been appreciated but, until recently, little attention has been give...
详细信息
The necessity of using effective absorbing boundary conditions (ABCs) to terminate microstrip or other planar waveguides in the FDTD method has long been appreciated but, until recently, little attention has been given in the literature to the best choice of ABC algorithm for this purpose. Although some comparisons of ABCs are now available they, unfortunately, differ in their conclusions. In the Letter the theoretical and numerical behaviour of some published ABCs are compared and the best ABC algorithm for this application is identified.
A method is presented to find a selected set of eigenvalues and the respective eigenvectors of the generalised eigenvalue problem Ax = lambda-Bx for large, sparse, real or complex, non-Hermitian matrices. Although the...
详细信息
A method is presented to find a selected set of eigenvalues and the respective eigenvectors of the generalised eigenvalue problem Ax = lambda-Bx for large, sparse, real or complex, non-Hermitian matrices. Although the method is clearly applicable to other problems, results are given of application to the vectorial finite element analysis of dielectric waveguides.
The propagation characteristics of a transversely magnetised MIS coplanar waveguide are studied. It is shown how the low-loss and slow-wave effects are efficiently combined with a relevant nonreciprocal propagation ph...
详细信息
The propagation characteristics of a transversely magnetised MIS coplanar waveguide are studied. It is shown how the low-loss and slow-wave effects are efficiently combined with a relevant nonreciprocal propagation phenomenon. This fact could be used for the design of nonreciprocal components suitable for integration.
A channel waveguide ring resonator was successfully fabricated using polymers synthesised from deuterated methacrylate and deuterated fluoromethacrylate. Resonance curves with a finesse of 14.8 and an extinction ratio...
详细信息
A channel waveguide ring resonator was successfully fabricated using polymers synthesised from deuterated methacrylate and deuterated fluoromethacrylate. Resonance curves with a finesse of 14.8 and an extinction ratio of 0.83 were obtained at a wavelength of 1.3 mum. The corresponding waveguide loss was estimated to be 0.10 dB/cm. In addition, the temperature and polarisation characteristics of the resonance were investigated.
For the first time the vertical integration of high-silica content low-loss channel waveguides on an Si substrate is reported. The fabrication process, which has made the vertical integration feasible, consists of a p...
详细信息
For the first time the vertical integration of high-silica content low-loss channel waveguides on an Si substrate is reported. The fabrication process, which has made the vertical integration feasible, consists of a practical multistep combination of flame hydrolysis deposition (FHD), photolithographic patterning and reactive ion etching. The successful application to a double integration of singlemode waveguides at 1.55-mu-m is also reported. This result, which has been possible thanks to the FHD peculiarities, by extending the optical interaction to a third dimension, opens a wide range of original and promising applications, such as vertically coupled devices or parallel optical signal processors, and it effectively increases the density of optical guided-wave functions available on the same substrate.
A new discretisation procedure based on a finite difference approach is presented for the analysis of arbitrary two-dimensional optical dielectric waveguides. It is based on a longitudinally variant discretisation gri...
详细信息
A new discretisation procedure based on a finite difference approach is presented for the analysis of arbitrary two-dimensional optical dielectric waveguides. It is based on a longitudinally variant discretisation grid that allows an accurate treatment of waveguide changes of geometry to be obtained. Comparisons with the well known beam propagation method show a strong improvement in accuracy and computational time saving.
Multiple 3-D discontinuities between rectangular ferrite loaded waveguides are analysed. This analysis is carried out by means of the coupled mode method, using a series expansion that is different from the classical ...
详细信息
Multiple 3-D discontinuities between rectangular ferrite loaded waveguides are analysed. This analysis is carried out by means of the coupled mode method, using a series expansion that is different from the classical one, combined with the modal matching method. Reasonable agreement is found between theoretical predictions and experimental results.
暂无评论