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5. One-Dimensional Silicon Nitride Grating Refractive Index Sensor Suitable for Integration With CMOS Detectors

Author

Shakoor, Abdul, Grande, Marco, Grant, James, and Cumming, David R.S.

Subjects
lcsh:Applied optics. Photonics, Atomic and Molecular Physics, Nanophotonics, lcsh:TA1501-1820, lcsh:QC350-467, diffraction gratings, Diffraction gratings, sensors, Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering, and Optics, lcsh:Optics. Light
Abstract

The transformation of nanophotonic sensors from laboratory-based demonstrations to a portable system to ensure widespread applicability in everyday life requires their integration with detectors for direct electrical read out. As complementary metal oxide semiconductor (CMOS) technology has revolutionized the electronics industry, the integration of nanophotonic structures with CMOS technology will also transform the sensing market. However, nanophotonic sensors have to fulfill certain requirements for their integration with CMOS detectors, such as operation in the visible wavelength range, operation in normal incidence configuration, use of CMOS compatible materials, and capability to give large optical intensity change due to resonance wavelength shift. In this paper, we have designed and developed one-dimensional silicon nitride grating structures that satisfy all these conditions simultaneously. The gratings can achieve 1 and 6 nm linewidths for the transverse-electric (TE) and transverse-magnetic (TM) polarizations, respectively, with 90% resonance depth. The experimental linewidth is 8 nm with 55% resonance depth, which is limited by the detector resolution. The experimental sensitivity of the device is 160 nm/refractive index unit (RIU), which translates to a very high intensity sensitivity of 1700%/RIU, which would enable sensing of very small changes in refractive index when integrated with a detector.

Published
2017

6. Performance Enhancement of PPMIM Drives by Using Three 3-Phase Four-Leg Inverters.

Author

Reddy, B. Prathap, Iqbal, Atif, Keerthipati, Sivakumar, Al-Hitmi, Mohammed, Hasan, Anwarul, Mehrjerdi, Hasan, Paraprath, Asokan, and Shakoor, Abdul

Subjects
PULSE width modulation, VECTOR spaces, SHORT circuits, FINITE element method, INDUCTION motors, TORQUE
Abstract

In this article, a multilevel inverter (MLI) scheme is proposed for 9-phase pole phase modulated induction motor (PPMIM) drives. The proposed inverter scheme is realized with the help of three 3-phase four-leg inverters. In 3-phase 12-pole mode (3PH-12PO), the proposed MLI supplies a 3-level voltage for each phase winding of the PPMIM drive with an improved harmonic profile, which results in better torque ripple. In this mode, the PPMIM drive performance is analyzed with a level shifted as well as phase shifted carrier based space vector pulse width modulation (SVPWM) techniques. On the other hand in 9-phase 4-pole mode (9PH-4PO), with help of phase grouping concept a 3-phase SVPWM implemented for enhancing the linear modulation of the 9-phase PPMIM drives by 15.4%. The fourth leg present in each 3-phase four-leg inverter is used effectively for suppressing the circulating currents in phase windings during 9PH-4PO operation. The proposed MLI is efficient to operate the PPMIM drive in both normal as well as fault conditions with rated power/torque. The proposed MLI-fed PPMIM drive performance with open circuit/short circuit of switch and source fault conditions are analyzed. The proposed MLI scheme is validated with the Ansys Maxwell finite element method (FEM) as well as laboratory testbed on a 5-hp 9-phase PPMIM drive under normal as well as open circuit switch/source fault conditions. [ABSTRACT FROM AUTHOR]

Published
2021
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7. Silicon Optical Modulators for Data Transmission in Different Wavelength Bands

Author

Thomson, David J., primary, Zhang, Weiwei, additional, Ebert, Martin, additional, Shakoor, Abdul, additional, Chen, Bigeng, additional, Alam, Shaif-ul, additional, Wang, Junjia, additional, Chen, Xia, additional, Mastronardi, Lorenzo, additional, Banakar, M., additional, Crudgington, Lee, additional, Li, Ke, additional, Gardes, Frederic Y., additional, Xu Brian Sia, Jia, additional, Wang, Wanjun, additional, Qiao, Zhongliang, additional, Li, Xiang, additional, Guo, Xin, additional, Wang, Hong, additional, Wilson, Peter, additional, Mashanovich, Goran Z., additional, Knights, Andy, additional, Cao, Wei, additional, Reed, Graham T., additional, Hagan, David, additional, Liu, Shenghao, additional, Meng, Fanfan, additional, Nedeljkovic, Milos, additional, Khokhar, Ali Z, additional, and Littlejohns, Callum G., additional

Published
2019
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9. Wide-range optical CMOS-based diagnostics

Author

Al-Rawhani, Mohammed A., primary, Cheah, Boon Chong, additional, Giagkoulovits, Christos, additional, Shakoor, Abdul, additional, Nagy, Bence, additional, Beeley, James, additional, and Cumming, David R. S., additional

Published
2017
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10. CMOS Nanophotonic Sensor With Integrated Readout System.

Author

Shakoor, Abdul, Cheah, Boon Chong, Al-Rawhani, Mohammed A., Grande, Marco, Grant, James, Gouveia, Luiz Carlos Paiva, and Cumming, David R. S.

Abstract

The measurement of nanophotonic sensors currently requires the use of external measuring equipment for their read-out such as an optical spectrum analyzer, spectrophotometer, or detectors. This requirement of external laboratory-based measuring equipment creates a “chip-in-a-lab” dilemma and hinders the use of nanophotonic sensors in practical applications. Making nanophotonic sensors usable in everyday life requires miniaturization of not only the sensor chip itself but also the equipment used for its measurement. In this paper, we have removed the need of external measuring equipment by monolithically integrating 1-D grating structures with a complementary metal-oxide-semiconductor (CMOS) integrated circuit having an array of photodiodes. By doing so, we get a direct electrical read-out of the refractive index changes induced when applying different analytes to grating structures. The gratings are made of CMOS compatible silicon nitride. Employing a nanophotonic sensor made of CMOS compatible material allows fabrication of the integrated sensor chip in a commercial CMOS foundry, enabling mass production for commercialization with low cost. Our results present a significant step toward transforming present laboratory-based nanophotonic sensors into practical portable devices to enable applications away from the analytical laboratory. We anticipate the work will have a major impact on technology for personalized medicine, environmental, and industrial sensing. [ABSTRACT FROM AUTHOR]

Published
2018
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11. Light generation in silicon photonic crystal cavities

Author

Galli, Matteo, primary, O'Faolain, Liam, additional, Gerace, Dario, additional, Lo Savio, Roberto, additional, Portalupi, Simone Luca, additional, Shakoor, Abdul, additional, Welna, Karl, additional, Andreani, Lucio C., additional, Krauss, Thomas F., additional, Irrera, Alessia, additional, Franzo, Giorgia, additional, and Priolo, Francesco, additional

Published
2011
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12. Subbandgap photoluminescence of Si photonic crystal nanocavity at room temperature

Author

Shakoor, Abdul, primary, O'Faolain, Liam, additional, Galli, Matteo, additional, Lo Savio, Roberto, additional, Portalupi, Simone Luca, additional, Welna, Karl, additional, Gerace, Dario, additional, Guizzetti, Giorgio, additional, Andreani, Lucio C., additional, Krauss, Thomas F., additional, Irrera, Alessia, additional, Franzo, Giorgia, additional, and Priolo, Francesco, additional

Published
2011
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13. Photoluminescence spectroscopy of silicon photonic crystal nanocavities

Author

Savio, Roberto Lo, primary, Portalupi, Simone Luca, additional, Galli, Matteo, additional, Gerace, Dario, additional, Andreani, Lucio C., additional, Shakoor, Abdul, additional, O'Faolain, Liam, additional, Krauss, Thomas F., additional, Irrera, Alessia, additional, Franzo, Giorgia, additional, and Priolo, Francesco, additional

Published
2011
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