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Diaa Khalil  - - - 
Top co-authors See all
Tarek A. Al-Saeed

18 shared publications

Department of Biomedical Engineering, Faculty of Engineering, Helwan University, Cairo Governorate 11795, Egypt

Tarik Bourouina

14 shared publications

Université Paris-Est, ESIEE Paris, ESYCOM EA 2552, 93162 Noisy-le-Grand, France

Yasser M. Sabry

11 shared publications

Faculty of Engineering, Ain-Shams University, Cairo 11566, Egypt

Khaled Kirah

10 shared publications

Engineering Physics Department, Faculty of Engineering, Ain Shams University, Abbasiya, Cairo, Egypt

Frédéric Marty

7 shared publications

Université Paris-Est, ESIEE Paris, ESYCOM EA 2552, 93162 Noisy-le-Grand, France

Publication Record
Distribution of Articles published per year 
(2009 - 2017)
Total number of journals
published in
PROCEEDINGS-ARTICLE 9 Reads 0 Citations Coupled-Cavity Optofluidic Fabry-Perot Resonators for Enhanced Volume Refractometry Mohamed Nabil Ali, Yasser M. Sabry, Fredric Marty, Tarik Bou... Published: 21 July 2017
Proceedings of The 7th International Multidisciplinary Conference on Optofluidics 2017, doi: 10.3390/optofluidics2017-04155
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This paper reports the design, fabrication and preliminary characterization of optofluidic Fabry-Perot micro coupled cavities enabling on-chip refractometry with large dynamic range. Large dynamic range refractometry is needed in several applications such as in portable food analyzers, where the quality of fruits and beverages are classified based on their Brix number, which indicates the sugar content. The Brix numbers is obtained from the refractive index using standard conversion tables [1-2], where the refractive index varies from 1.333 (0 oB) to 1.49 (80 oB). The conventional design of integrated refractometer is based on Fabry-Perot cavity, in which the wavelength of longitudinal modes shifts with the change in the refractive index of the filling medium [3-4]. Their dynamic range is usually in the order of 10-3, limited by the free spectral range (FSR) of the micro cavity. Therefore, the food analyzers are usually based on volume optics components and the change of the refraction angle with the change in the refractive index that allows for the large dynamic range of sensing. In this work, we report a novel design based on cascading two coupled Fabry-Perot micro cavities allowing for orders of magnitude increase in the FSR besides the decrease in the linewidth which enhances the resolution as well. Fig. 1 shows the schematic diagram of the new design and the idea of operation. The lengths of the two cavities are slightly different and adjusted such that some modes are suppressed after each allowed mode. The use of Si/Air layers to form the Bragg mirror with thickness of 3.8/3.6 mm allowed us to achieve designs with mode separation of 40 nm around a wavelength of 1550 nm. Fig. 2 shows a SEM photo of part of the fabricated structures. The fabrication was done using standard MEMS technology in which DRIE process is used to make a 150 mm deep etching in Si to form the Bragg mirrors, fiber grooves, and the microfluidic channels and ports. Test structures in the form of single cavities and mirrors were also fabricated on the same chip. Fig. 3 shows the measured transmittance of one of the fabricated coupled-cavities together with the measured transmittance of the single cavity corresponding to one of them. The single cavity has a length of 128 mm and the coupled-cavities have lengths L1 = 160 mm and L2 = 128 mm as referred to Fig. 1. The mirrors are composed of two Si layers in both cases. We can see the increase in the FSR achieved in the coupled cavity which is about 3 times as the single cavity and also the reduction in the line-width by less than half. In fact the technology tolerance, especially the over-etching, had a great effect on the fabricated structures. The fabricated mirrors had a wider bandwidth than expected and we could obtain a much larger FSR in the coupled-cavity. In some designs we obtained only one peak in the whole measured band of 140 nm.
Proceedings of The 7th International Multidisciplinary Conference on Optofluidics 2017, doi: 10.3390/optofluidics2017-04195
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In this work, we present the design and characterization of a 1xN beam splitter based on an MMI waveguide fabricated on MEMS technology. The proposed structure also has the advantage of allowing the splitter to be used at wavelengths below the 1.1 µm silicon cut off wavelength that is needed for many optofluidic applications. A compact splitter design is achieved by guiding the light in air in a parallel plate waveguide structure with the lowest achievable guiding refractive index, with paired excitation in the input and parabolic tapering in the waveguide width along its length. The structure is simulated at different wavelengths using a wide angle FD-BPM technique. Measurement results of the fabricated structure are also shown at wavelengths of 1310 nm and 980 nm.
Article 2 Reads 1 Citation Electrostatic Comb-Drive Actuator with High In-Plane Translational Velocity Yomna M. Eltagoury, Mostafa Soliman, Yasser M. Sabry, Mohamm... Published: 17 October 2016
Micromachines, doi: 10.3390/mi7100188
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This work reports the design and opto-mechanical characterization of high velocity comb-drive actuators producing in-plane motion and fabricated using the technology of deep reactive ion etching (DRIE) of silicon-on-insulator (SOI) substrate. The actuators drive vertical mirrors acting on optical beams propagating in-plane with respect to the substrate. The actuator-mirror device is a fabrication on an SOI wafer with 80 μm etching depth, surface roughness of about 15 nm peak to valley and etching verticality that is better than 0.1 degree. The travel range of the actuators is extracted using an optical method based on optical cavity response and accounting for the diffraction effect. One design achieves a travel range of approximately 9.1 µm at a resonance frequency of approximately 26.1 kHz, while the second design achieves about 2 µm at 93.5 kHz. The two specific designs reported achieve peak velocities of about 1.48 and 1.18 m/s, respectively, which is the highest product of the travel range and frequency for an in-plane microelectromechanical system (MEMS) motion under atmospheric pressure, to the best of the authors’ knowledge. The first design possesses high spring linearity over its travel range with about 350 ppm change in the resonance frequency, while the second design achieves higher resonance frequency on the expense of linearity. The theoretical predications and the experimental results show good agreement.
Article 3 Reads 3 Citations Diffraction effects in optical microelectromechanical system Michelson interferometers Tarek A. Al-Saeed, Diaa A. Khalil Published: 08 July 2010
Applied Optics, doi: 10.1364/ao.49.003960
DOI See at publisher website
Article 2 Reads 2 Citations Dispersion compensation in moving-optical-wedge Fourier transform spectrometer Tarek A. Al-Saeed, Diaa A. Khalil Published: 06 July 2009
Applied Optics, doi: 10.1364/ao.48.003979
DOI See at publisher website