Montasir Qasymeh

Quadratic Electro-Optic Kerr Effect: Applications to Photonic Devices

We propose novel applications of the quadratic electro-optic Kerr effect to photonic devices. Specifically in this work, two new illustrative examples are described, namely an electrically controlled multistable switch (ECMS), and an electrically tunable Bragg grating (ETBG). Their functionality is based on the third-order nonlinearity in an isotropic medium. On one hand, we note that the first key feature is the all-optical as well as electro-optical control/tunability. This can be achieved only in the third-order nonlinear material as opposed to a more frequently used linear electro-optic effect exploited in optical crystals. On the other hand, the second important key feature is the availability of integrated and compatible materials that show third order nonlinearity. In the first application proposed here, ECMS, the interplay between the quadratic electro-optic and all-optical Kerr effects is crucial for its tunable operation and leads to an interesting feature of storing an electrical information optically. In the second example, ETBG, employing the quadratic electro-optic effect makes it attractive thanks to the existence of the third-order nonlinearity in many interesting isotropic materials that are suitable for device integration. Devices such as modulators, switches, mixers, variable attenuators or optical limiters can be designed.

Electrically and optically controlled cross-polarized wave conversion

Light wave propagation in third-order nonlinear media with applied external electric field is investigated. Interplay between the nonlinear electro-optic and all-optical effects is examined theoretically. Energy exchange between the orthogonal light polarizations, the cross polarization conversion, results. The assisting external field acts as either the effect-enhancing or functionality-controlling parameter. Various materials such as silica glass, silicon, other bulk and quantum well semiconductors, organic materials, and particle-doped nanostructures are referred to as possible candidates for device implementations. Numerical estimates of achievable parameters in a selected suitable material are discussed.

Electronic control of soliton power transfer in silicon nanocrystal waveguides

We demonstrate numerically that the power transfer from one polarization component of a (1+ 1)D vector spatial soliton to the other in a birefringent nonlinear medium can be controlled via the electro-optic Kerr effect by varying the externally applied electric field. We show how several all-optical operations involving fundamental vector solitons can be electronically controlled. We also discover that the split-up of the higher-order vector solitons due to the two-photon absorption (TPA) can be suppressed by adjusting the external electric field. The soliton trapping along the slow optical axis is realized by a planar waveguide, filled with a silicon-nanocrystal material. The external electric field is applied along the fast optical axis of the waveguide.

Optical Wave Propagation in Kerr Media

Optical wave propagation and interaction are important effects usable in designing and implementing various photonic devices ranging from passive splitters to active switches to light amplifiers. The material aspects are crucial as strong effects are desirable for efficient and robust devices. Electronics has its silicon that is an amazing rather universal material that makes it possible to implement microelectronics chips of unthinkable performance and functionalities. Photonics does not have such a common material, and therefore one has to choose suitable material system for a given application. However, with silicon being the best technologically mastered material, attempts have been made to employ it also in the implementation of photonic functions. Examples include electro-optic modulators and, of course, high speed photodetectors.

Deflection Sensors Utilizing Optical Multi‐Stability

Deflection sensors have attracted significant attention due to their wide application in pressure and temperature measurements in practical systems. Several techniques have been proposed, studied, and tested to realize optical deflection sensor elements, including Mach‐Zehnder (MZI), and Fabry‐Perot interferometers. In this work, a novel optical deflection sensor that is comprised of two cascaded optical resonators is proposed and analyzed. The proposed structure is designed to operate in the multi‐stable (input to output) regime. As the first resonator is equipped with a movable mirror, which is connected to a diaphragm in order to sense changes in deflection, the second resonator is filled with non‐linear material. It is demonstrated that such a structure has a novel memory property, aside from having the ability to yield instant deflection measurements. This novel property is attributed to the non‐linear refractive index of the medium of the second resonator. Furthermore, the sensor sensitivity (which ...

Photorefractive Silicon Waveguides: A Theoretical Investigation

We show theoretically that the photorefractive effect (PR) is realizable in silicon waveguides, providing a proper external electrical field is applied. Moreover, we propose, analyze and discus a novel silicon-based PR ring oscillator modality.

Ultrashort pulse polarization control in silicon waveguides

The nonlinear polarization dynamics of ultrashort optical pulses propagating in a low birefringent silicon waveguide is theocratically and numerically studied, with a static electric field applied across the waveguide. It is shown that the pulse shape and polarization evolution can be efficiently controlled by adjusting the magnitude of the applied dc field. It is also demonstrated that the polarization instability regime can be achieved in such waveguides - despite the presence of strong linear losses - by appropriately engineering the spatial distribution of the control field along the waveguide. The simulations indicate that short silicon waveguides can serve as a viable platform for developing re-configurable all-optical and/or optically assisted electro-optic devices in the spectral range spanning from near- to mid-infrared.

Re-configurable all-optical devices based on electrically controlled cross-polarized wave conversion

An electrically controlled all-optical cross-polarization wave conversion has been investigated theoretically and modeled numerically. The discussed features under these conditions indicate a future potential for functional re-configurable all-optical devices.

TIRE of 2D Binary Gratings with Combined Fe-SiO 2 Dots

Theoretical model for total internal reflection ellipsometry (TIRE) is used to testing of an influence of metallic elements in 2D grating structure. The influence of iron volume in the dots and protection metallic layers is analyzed in detail.

Photonic Devices Based on Programmable Optical Nonlinearity: Tunable Bragg Grating

The electronic signal is used to control optical nonlinear properties of a third-order nonlinearity material. An example of a photonic device design utilizing such electronic control is discussed.