Ahmad B. Ayoub

Silicon plasmonic-integrated sensor

We propose a novel structure with two input and output silicon waveguide ports separated by the Insulator-Metal- Insulator channel deposited on silicon nitride base. In principle, both the top surface insulator/metal interface and bottom surface can support SPP a decoupled modes. Once the SPP modes excited input silicon waveguide, the SPP signals from the two optical branches (the top and bottom interfaces) propagate to the output silicon waveguide. At the output waveguide both branches interfere with each other and modulate the far-field scattering. The top surface is considered as the sensing arm of this plasmonic Mach-Zehnder interferometer (MZI). The bottom surface is considered as the reference arm of the sensor. High sensitivity and small foot print is achieved using this integrated simple plasmonic design. The combination of sensitive interferometric techniques and the optimization process of the design and the material yields to enhanced sensitivities up to 3000 nm/RIU.

Leap-frog-based BPM (LF-BPM) method for solving nanophotonic structures

In this paper, we propose an efficient approach to solve the BPM equation. By splitting the complex field into real and imaginary parts, the method is proved to be at least 30% faster than the conventional BPM. This method was tested on several optical components to test the accuracy.

High-performance optical modulator using ultra-thin silicon waveguide in SOI technology

High performance optical structures based on new platform for the design of photonic structures are proposed in this work. The platform is previously proposed and is based on the design of an ultra thin waveguide with narrow lateral thickness with low confined field inside the core waveguide which enables using this waveguide for building high performance photonic based sensors and modulators. An MZI based modulator is reported with extinction ratio of 20.36 dB. These values resulted in high performance photonic structures as compared to the conventional waveguide based structures delimiting some of the constraints when using photonic structures. Keywords: interference, modulation, sensing, photonic structures, Mach-Zehnder

High performance silicon Mach-Zehnder interferometer based photonic modulator

A new design for silicon Mach-Zehnder photonic interferometer with a different cross-sectional area than that for conventional silicon waveguide is proposed. The structure has the potential to be used as a modulator with extremely large extinction ratio as compared to conventional silicon waveguides based MZI modulators. This enabled using our design in different micro-scale applications including optical sensing and modulation using photonic structures.

Ultra-sensitive silicon-photonic on-chip sensor using microfabrication technology

In this paper, we propose a new design for Mach-Zehnder interferometer with different cross-sectional area than that for conventional silicon waveguide. The structure has a high sensitivity towards the surrounding media as compared to conventional silicon waveguides. This enabled using our design in different applications including optical sensing and modulation.

Novel BPM technique using leap-frog technique

In this paper, a new solution for the wave equation using the BPM technique is proposed. The basic idea of this new technique is based on reformulating the BPM equation to separate the real and imaginary parts and utilizes real system matrices only for the propagation steps. The updated equation exploits leap-frog method to couple the real and imaginary parts of the field at each propagation step. A comparison between the proposed method of solution and the conventional one is made and show that the proposed technique in solving the BPM equation get an accurate results with more time efficient way. Our method is proved to be at least 30% faster than the conventional BPM in solving waveguide problems. Such method can open the door towards efficient computational algorithms for solving complex systems.

Fiber-optic-based interferometric sensor

A fiber based plasmonic sensor design is proposed. In principle, both the top surface insulator/metal interface and bottom surface can support SPP decoupled modes. The combination of sensitive interferometric techniques and the optimization process of the design and the material yields to enhanced sensitivities in range of 11000 nm/RIU.

Nanoscale plasmonic Metal-Insulator-Metal architecture for gas sensing applications

We propose a novel structure for a plasmonic gas sensor. The idea of operation is based on Metal-Insulator-Metal (MIM) approach. The plasmonic slot mode enables high confinement in the insulator gap which is the gas being sensed which leads to high sensitivity. High sensitivity and small foot print is achieved through this plasmonic design. Several optimization processes yield high sensitivity as high as 1,536 nm/RIU, FWHM down to 9.8 nm and FOM of 156 which is the greatest FOM to our knowledge.

Nanoscale highly selective plasmonic multi-channnel demultiplexer

A highly selective plasmonic demultiplexer based on a plasmonic slot waveguide platform is proposed. The structure is optimized as an add drop multiplexer/demultiplexer. The optimal design is targeting minimum FWHM. The device is optimal quad multiplexer/demultiplexer has FWHM of 9.8 nm for each channel with a high output transmission near the 1550 nm. The proposed structure is simple, can be easily fabricated. Extended optimization was performed that enabled the multiplexed signal to have FWHM of 8.16 nm with peak power of 30 % near the 1300 nm. The structure can be utilized for double channel multiplexing applications and more by doing the needed optimization for such high scalability.