Sharif Digital Repository

In this paper, we present the design guidelines for a tunable optical isolator in an SOI-based ring resonator with two small time-modulated regions. By considering a physical model, the proper geometrical and modulation parameters are designed, based on a standard CMOS foundry process. The effect of the variation of the key parameters on the performance of the isolator is explained by two counter-acting mechanisms, namely the separation between the resonance frequencies of counter-rotating modes and energy transfer to the side harmonic. We show that there is a trade-off between these parameters to obtain maximum isolation. Consequently, by applying the quadrature phase difference one can... 

3D imaging technologies are applied in numerous areas, including self-driving cars, drones, and robots, and in advanced industrial, medical, scientific, and consumer applications. 3D imaging is usually accomplished by finding the distance to multiple points on an object or in a scene, and then creating a point cloud of those range measurements. Different methods can be used for the ranging. Some of these methods, such as stereovision, rely on processing 2D images. Other techniques estimate the distance more directly by measuring the round-trip delay of an ultrasonic or electromagnetic wave to the object. Ultrasonic waves suffer large losses in air and cannot reach distances beyond a few... 

The electric field of the modes of semiconductor microring lasers (SMRLs) in the presence of bus waveguide reflections are linear combinations of the clock wise (CW) and the counter clock wise (CCW) electric fields. The mode structures can be controlled by the waveguide reflection coefficients. The power ratio and phase difference of the CW and CCW fields of one mode is proportional to the ratio of the reflection coefficients of the left and right waveguides. It is shown that the degenerate CW and CCW modes in the presence of bus waveguide reflections are split into two modes with different frequencies. Employing these new modes, SMRL can be used as an element to design flip-flops used in... 

This paper a simple semi-analytical model for calculation of the time evolution and spatial variation of the electric field in microring resonators in the presence of The Kerr effect and two-photon absorption (TPA) is presented. The theoretical analysis is based on the delayed feedback model, which is well known in microring theory. The model is applied to the Chalcogenide glass and AlGaAs microrings to study the Kerr and TPA effects on the spatial and temporal variation of electric field respectively across the microring. The effects of microring parameters and input signal shapes on the transient behavior are taken into consideration. It is shown that, the results are in good agreement...