Degenerate four wave mixing of light at 1.055-mu-m guided in poly[4,6-decadiyne-1,10 diol bis(n-butoxycarbonylmethylurethane)] planar waveguides has been observed. Diffraction efficiencies of up to 24% have been obtai...
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Degenerate four wave mixing of light at 1.055-mu-m guided in poly[4,6-decadiyne-1,10 diol bis(n-butoxycarbonylmethylurethane)] planar waveguides has been observed. Diffraction efficiencies of up to 24% have been obtained, with a laser peak power of 2 W. Approximately 50% of the nonlinear mechanism can be attributed to the ultrafast molecular hyperpolarisability of the polymer.
A planar waveguide containing a nonlinear film whose thickness varies in the transverse direction can be used to simulate propagation in a one (transverse)-dimensional medium with constant refractive index but a spati...
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A planar waveguide containing a nonlinear film whose thickness varies in the transverse direction can be used to simulate propagation in a one (transverse)-dimensional medium with constant refractive index but a spatially varying nonlinearity. This idea is illustrated by finding the steady-state solutions for several examples.
Planar optical waveguides were fabricated by proton implantation at 0.8 MeV in single crystal of lithium niobate (LiNbO3;Y-cut). Their thermal stability was investigated by measuring the evolution of the ordinary effe...
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Planar optical waveguides were fabricated by proton implantation at 0.8 MeV in single crystal of lithium niobate (LiNbO3;Y-cut). Their thermal stability was investigated by measuring the evolution of the ordinary effective indices (TE modes) on thermal annealing achieved in air and in the range of 250 to 350-degrees-C. This evolution is compared to that of the nuclear damage induced by implantation effects which is analysed by channeling Rutherford backscattering. It is shown that an optical barrier does exist and optical modes can be excited, although the lattice dammage is reduced by annealing to a value as low as the one of an unimplanted sample. Since the observed thermal stability of the waveguides is rather good, proton implantation in LiNbO3 offers high potentiality for the elaboration of optical integrated devices.
A simple vector correction is applied to the polarised solution obtained from a single component wave equation. The resulting propagation constants are shown to be indistinguishable from six-component vector finite el...
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A simple vector correction is applied to the polarised solution obtained from a single component wave equation. The resulting propagation constants are shown to be indistinguishable from six-component vector finite element results used as a benchmark. This considerably strengthens the validity of the polarised solution for the accurate modelling of rib and stripe waveguides, and shows that emphasis should be placed on finding quick and reliably accurate methods for the polarised approximation. Only then does the vector correction itself become accurate.
A new, low-loss, metal-insulator-metal (MIM) coplanar waveguide on periodically screened semi-insulating GaAs substrate is described. A theoretical analysis using the Floquet theorem shows wavelength reductions in the...
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A new, low-loss, metal-insulator-metal (MIM) coplanar waveguide on periodically screened semi-insulating GaAs substrate is described. A theoretical analysis using the Floquet theorem shows wavelength reductions in the range 7-24 along with very high Q at frequencies up to 100 GHz.
The analysis of a class of planar transmission lines in composite uniform waveguides which have a circular boundary over part of the cross-section and a rectangular boundary over the remainder is introduced. It is sho...
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The analysis of a class of planar transmission lines in composite uniform waveguides which have a circular boundary over part of the cross-section and a rectangular boundary over the remainder is introduced. It is shown that the method of lines can be applied to such composite structures by taking advantage of the canonical geometry in each region. Results for the dispersion characteristics and impedance of a finline in such a structure are calculated.
A new compact two dimensional FDTD for the dispersion analysis of guided wave structures, a traditionally three dimensional task, is proposed. To prove the validity of this method, the results for a boxed microstrip l...
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A new compact two dimensional FDTD for the dispersion analysis of guided wave structures, a traditionally three dimensional task, is proposed. To prove the validity of this method, the results for a boxed microstrip line on a sapphire substrate are presented and compared with available results.
It is well known that in analysing symmetric directional coupler problems only half of the cross-section need be considered, thereby shortening CPU time and reducing the computer memory needed. This simplicity disappe...
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It is well known that in analysing symmetric directional coupler problems only half of the cross-section need be considered, thereby shortening CPU time and reducing the computer memory needed. This simplicity disappears in the case of important devices such as the asymmetric directional coupler. The paper proposes a new methodology which allows fine-mesh finite difference analysis for the modal indices and field profiles of the two lowest supermodes of such an asymmetric structure.
Blue light was generated at room temperature by quasiphase-matched second harmonic generation in planar and channel lithium tantalate (LiTaO3) annealed proton exchange wave-guides using the d33 nonlinear coefficient. ...
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Blue light was generated at room temperature by quasiphase-matched second harmonic generation in planar and channel lithium tantalate (LiTaO3) annealed proton exchange wave-guides using the d33 nonlinear coefficient. Alternating ferro-electric domains for third order quasiphase matching were created by poling the substrates with a periodic electric field.
Autocorrelation measurements of picosecond optical pulses have been carried out using a quasiphase-matching channel waveguide in lithium niobate as the doubling element. The use of waveguides instead of bulk crystals ...
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Autocorrelation measurements of picosecond optical pulses have been carried out using a quasiphase-matching channel waveguide in lithium niobate as the doubling element. The use of waveguides instead of bulk crystals can drastically reduce the demands on power level. A pulse duration of 12 ps was measured for pulses from a gain-switched AlGaAs laser diode with ion-bombarded facets.
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