A. Omar

Design of Compact Integrated InGaAsP/InP Polarization Controller Over the C-Band

In this paper, we propose a compact integrated InGaAsP/InP polarization controller circuit. The proposed circuit transforms any incoming state of polarization (SOP) to any required SOP. It consists of two polarization beam splitters/ combiners, two polarization converters, a tunable power coupler, and a phase shifter, which are integrated on a single chip. The controller size is 6000 mum times 9.7 mum. Optical characteristics of the controller are evaluated by computer simulation using a 3-D full-vectorial beam propagation method. Simulation results show that the insertion loss is less than 3.2 dB, and the extinction ratio is more than -22 dB for the wavelength range from 1.53 to 1.56 mum.

SPIN-COHERENT TRANSPORT IN MESOSCOPIC INTERFERENCE DEVICE

We investigate the quantum size effect in the phase coherent mesoscopic ring. A quantum dot is embedded in one arm and it is connected to one lead via tunnel barrier. Both Aharonov–Casher and Aharonov–Bohm effects are studied. A spin-dependent conductance has been deduced and it depends on the intrinsic parameters. Our results show that the strength of spin-orbit coupling depends on the size of the present device. This investigation is valuable for fabricating such spintronics devices.

The Design and Optimization of an Ion-Exchanged Polarization Converter Using a Genetic Algorithm

In this work, a genetic algorithm is used for the optimization of the design parameters of an integrated optical polarization converter on a glass substrate. The algorithm is applied to find the minimum possible length for the converter. The required asymmetry for the structure is realized with the aid of a cleaving process following the ion-exchange process. Simulation results show the possibility of realizing such a low-cost integrated converter. The obtained results demonstrate the importance of using such an algorithm in integrated optics problems where several design parameters such as the geometrical dimensions, the temperature, and the time duration are to be optimized.

Assessment of the NM-Lines Sensitivity for Measurement Errors

Abstract In this work we investigate the sensitivity of the recently proposed NM-lines technique with respect to the error in the angle measurement in comparison with the conventional M-lines technique. The obtained results show that the NM-lines technique allows us to reduce the effect of the measurement errors and thus obtain better results for a given angular resolution.

D5. Design of InGaAsP/InP compact integrated lyot depolarizer

In this paper, we propose and demonstrate an integrated optics InGaAsP/InP Lyot depolarizer. Detailed simulation, using three-dimensional full vectorial BPM (3D-VBPM), shows that a high index contrast material allows the design of a compact polarization insensitive depolarizer. Output degree of polarization less than 0.1 is obtained for light sources with spectral widths larger than 25nm.

Modeling of subwavelength problems using modal techniques

A modal technique is used for modeling the problem of light propagation through masks with subwavelength features. Different approaches for the proper treatment of the excitation and the finite window are discussed. Results obtained using the technique are compared to those obtained by the volume integral equation method and the finite difference time domain method. The proposed technique shows very good agreement with both methods as well as significant reduction in the simulation time compared to the finite difference time domain method.

Design of Compact Integrated InGaAsP/ InP Polarization-Insensitive Tunable 2×2 Power Coupler over the C-band

We propose and demonstrate an integrated InGaAsP/InP tunable power coupler, with very low polarization sensitivity. The dimensions of the power coupler are 1268 mum times 8.7 mum. Simulation using three dimensional full Vectorial Beam Propagation Method (3D-VBPM) shows that the losses of the coupler are less than 0.6 dB for wavelengths from 1.53 mum to 1.56 mum.

Comparison of the N times mode-lines technique to the inverse technique in refractive index profile reconstruction

A single-mode waveguide is fabricated using ion exchange in a molten bath of KNO 3 salt. The mode effective index is measured using a mode-lines (M-lines) experiment. The waveguide is then etched, and the M-lines experiment is performed again. The two measurements are sufficient for refractive index profile (RIP) reconstruction, which is assumed to be Gaussian. The reconstructed profile is checked using a numerical technique and is then compared to the inverse technique, showing the inverse technique limitations.