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Ali Z. Khokhar  - - - 
Top co-authors See all
Nikolaj Gadegaard

169 shared publications

School of Engineering, University of Glasgow, Glasgow, UK

Milos Nedeljkovic

88 shared publications

Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK

Vittorio M. N. Passaro

44 shared publications

Electrical and Information Engineering, Politecnico di Bari, Bari, ba Italy 70125 ()

Youfang Hu

21 shared publications

Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK; s:(A.Z.K.);(M.N.);(S.A.R.);(Y.H.);(G.Z.M.)

Nikolaos Kehagias

20 shared publications

Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain

Publication Record
Distribution of Articles published per year 
(2010 - 2018)
Total number of journals
published in
Publications See all
PROCEEDINGS-ARTICLE 0 Reads 0 Citations 56 Gbps Si/GeSi integrated EAM Lorenzo Mastronardi, Mehdi Banakar, Ali Z. Khokhar, Nannicha... Published: 25 October 2018
Nanophotonics and Micro/Nano Optics IV, doi: 10.1117/12.2502709
DOI See at publisher website
Article 0 Reads 1 Citation Integrated 3D Hydrogel Waveguide Out-Coupler by Step-and-Repeat Thermal Nanoimprint Lithography: A Promising Sensor Devi... Achille Francone, Timothy Kehoe, Isabel Obieta, Virginia Sae... Published: 26 September 2018
Sensors, doi: 10.3390/s18103240
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
Hydrogel materials offer many advantages for chemical and biological sensoring due to their response to a small change in their environment with a related change in volume. Several designs have been outlined in the literature in the specific field of hydrogel-based optical sensors, reporting a large number of steps for their fabrication. In this work we present a three-dimensional, hydrogel-based sensor the structure of which is fabricated in a single step using thermal nanoimprint lithography. The sensor is based on a waveguide with a grating readout section. A specific hydrogel formulation, based on a combination of PEGDMA (Poly(Ethylene Glycol DiMethAcrylate)), NIPAAm (N-IsoPropylAcrylAmide), and AA (Acrylic Acid), was developed. This stimulus-responsive hydrogel is sensitive to pH and to water. Moreover, the hydrogel has been modified to be suitable for fabrication by thermal nanoimprint lithography. Once stimulated, the hydrogel-based sensor changes its topography, which is characterised physically by AFM and SEM, and optically using a specific optical set-up.
Article 3 Reads 0 Citations N-rich silicon nitride angled MMI for coarse wavelength division (de)multiplexing in the O-band Thalia Dominguez Bucio, Ali Z. Khokhar, Goran Z. Mashanovich... Published: 07 March 2018
Optics Letters, doi: 10.1364/ol.43.001251
DOI See at publisher website ABS Show/hide abstract
We report the design and fabrication of a compact angled multimode interferometer (AMMI) on a 600 nm thick N-rich silicon nitride platform (n=1.92) optimized to match the International Telecommunication Union coarse wavelength division (de)multiplexing standard in the O telecommunication band. The demonstrated device exhibited a good spectral response with Δλ=20 nm, BW3 dB∼11 nm, IL<1.5 dB, and XT∼20 dB. Additionally, it showed a high tolerance to dimensional errors <120 pm/nm and low sensitivity to temperature variations <20 pm/°C, respectively. This device had a footprint of 0.02 mm×1.7 mm with the advantage of a simple design and a back-end-of-line compatible fabrication process that enables multilayer integration schemes due to its processing temperature <400°C.
PROCEEDINGS-ARTICLE 0 Reads 0 Citations Group IV mid-infrared devices and circuits Jordi Soler-Penadés, Wei Cao, Ahmed Osman, Yangbo Wu, Ali Z.... Published: 23 February 2018
Integrated Optics: Devices, Materials, and Technologies XXII, doi: 10.1117/12.2289531
DOI See at publisher website
PROCEEDINGS-ARTICLE 0 Reads 0 Citations Waveguide integrated graphene mid-infrared photodetector Zhibo Qu, Milos Nedeljkovic, Jordi Soler-Penadés, Ali Z. Kho... Published: 22 February 2018
Silicon Photonics XIII, doi: 10.1117/12.2290476
DOI See at publisher website
PREPRINT 0 Reads 0 Citations Ultrafast perturbation maps as a quantitative tool for testing of multi-port photonic devices Kevin Vynck, Nicholas J. Dinsdale, Bigeng Chen, Roman Bruck,... Published: 19 February 2018
ABS Show/hide abstract
Advanced photonic probing techniques are of great importance for the development of non-contact wafer-scale testing of photonic chips. Ultrafast photomodulation has been identified as a powerful new tool capable of remotely mapping photonic devices through a scanning perturbation. Here, we develop photomodulation maps into a quantitative technique through a general and rigorous method based on Lorentz reciprocity that allows the prediction of transmittance perturbation maps for arbitrary linear photonic systems with great accuracy and minimal computational cost. Excellent agreement is obtained between predicted and experimental maps of various optical multimode-interference devices, thereby allowing direct comparison of a device under test with a physical model of an ideal design structure. In addition to constituting a promising route for optical testing in photonics manufacturing, ultrafast perturbation mapping may be used for design optimization of photonic structures with reconfigurable functionalities.