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Full-Text Articles in Engineering

Properties Of Exchange Coupled All-Garnet Magneto-Optic Thin Film Multilayer Structures, Mohammed Nur-E-Alam, Mikhail Vasilev, Viacheslav A. Kotov, Dmitry Balabanov, Ilya Akimov, Kamal Alameh Jan 2015

Properties Of Exchange Coupled All-Garnet Magneto-Optic Thin Film Multilayer Structures, Mohammed Nur-E-Alam, Mikhail Vasilev, Viacheslav A. Kotov, Dmitry Balabanov, Ilya Akimov, Kamal Alameh

Research outputs 2014 to 2021

The effects of exchange coupling on magnetic switching properties of all-garnet multilayer thin film structures are investigated. All-garnet structures are fabricated by sandwiching a magneto-soft material of composition type Bi1.8Lu1.2Fe3.6Al1.4O12 or Bi3Fe5O12:Dy2O3 in between two magneto-hard garnet material layers of composition type Bi2Dy1Fe4Ga1O12 or Bi2Dy1Fe4Ga1O12:Bi12O3. The fabricated RF magnetron sputtered exchange-coupled all-garnet multilayers demonstrate a very attractive combination of …


Recent Developments In Magneto-Optic Garnet-Type Thin-Film Materials Synthesis, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh Jan 2014

Recent Developments In Magneto-Optic Garnet-Type Thin-Film Materials Synthesis, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

Research outputs 2014 to 2021

Magneto-optic (MO) garnets are used in a range of applications in nanophotonics, integrated optics, communications and imaging. Bi-substituted iron garnets of different compositions are the most useful class of materials in applied magnetooptics due to their excellent MO properties (large Faraday effect) and record-high MO figure of merit among all semitransparent dielectrics. It is highly desirable to synthesise garnets which possess simultaneously a high MO figure of merit and large uniaxial magnetic anisotropy. However, the simultaneous optimization of several material properties and parameters can be difficult in single-layer garnet thin films, and it is also challenging to prepare films with …


Recent Developments In Magneto-Optic Garnet-Type Thin-Film Materials Synthesis, Mohammad Nur E Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh Jan 2013

Recent Developments In Magneto-Optic Garnet-Type Thin-Film Materials Synthesis, Mohammad Nur E Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

Research outputs 2013

Magneto-optic (MO) garnets are used in a range of applications in nanophotonics, integrated optics, communications and imaging. Bi-substituted iron garnets of different compositions are the most useful class of materials in applied magneto- optics due to their excellent MO properties (large Faraday effect) and record-high MO figure of merit among all semi- transparent dielectrics. It is highly desirable to synthesise garnets which possess simultaneously a high MO figure of merit and large uniaxial magnetic anisotropy. However, the simultaneous optimization of several material properties and parameters can be difficult in single-layer garnet thin films, and it is also challenging to prepare …


Garnet Multilayer Thin Film Structure With Magnetostatically-Altered And Improved Magnetic Properties Prepared By Rf Magnetron Sputtering, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh Jan 2011

Garnet Multilayer Thin Film Structure With Magnetostatically-Altered And Improved Magnetic Properties Prepared By Rf Magnetron Sputtering, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

Research outputs 2011

We prepare an all-garnet multilayer film structure by sandwiching a magneto-soft garnet material in between two magneto-hard garnet materials with high bismuth substitution levels using RF magnetron sputtering technique and investigate the microstructure and the effects of magnetostatic inter-layer coupling on magnetic properties. Both types of the Bi-substituted magneto-optic garnet materials used possess excellent optical, magnetic and magneto-optical properties suitable for the application in different new and emerging technologies in optics and photonics. Garnet layers of composition type Bi2Dy1Fe4Ga1O12 have strong perpendicular magnetic anisotropy and Bi1.8Lu1.2Fe3.6Al1.4O12 magneto-soft layer features magnetization behavior similar to that of in-plane magnetized films. The all-garnet …


Metal-Semiconductor-Metal (Msm) Photodetectors With Plasmonic Nanogratings, Narottam K. Das, Ayman Karar, C L Tan, Mikhail Vasiliev, Kamal Alameh, Yong Tak Lee Jan 2011

Metal-Semiconductor-Metal (Msm) Photodetectors With Plasmonic Nanogratings, Narottam K. Das, Ayman Karar, C L Tan, Mikhail Vasiliev, Kamal Alameh, Yong Tak Lee

Research outputs 2011

We discuss the light absorption enhancement factor dependence on the design of nanogratings inscribed into metal-semiconductor-metal photodetector (MSM-PD) structures. These devices are optimized geometrically, leading to light absorption improvement through plasmon-assisted effects. Finite-difference time-domain (FDTD) simulation results show ~50 times light absorption enhancement for 850 nm light due to improved optical signal propagation through the nanogratings. Also, we show that the light absorption enhancement is strongly dependent on the nanograting shapes in MSM-PDs.


Groove Shape-Dependent Absorption Enhancement Of 850 Nm Msm Photodetectors With Nano-Gratings, Narottam Das, Ayman Karar, Mikhail Vasiliev, Chee Leong Tan, Kamal Alameh, Yong Tak Lee Jan 2010

Groove Shape-Dependent Absorption Enhancement Of 850 Nm Msm Photodetectors With Nano-Gratings, Narottam Das, Ayman Karar, Mikhail Vasiliev, Chee Leong Tan, Kamal Alameh, Yong Tak Lee

Research outputs pre 2011

Finite difference time-domain (FDTD) analysis is used to investigate the light absorption enhancement factor dependence on the groove shape of the nano-gratings etched into the surfaces of metal-semiconductor-metal photodetector (MSM-PD) structures. By patterning the MSM-PDs with optimized nano-gratings a significant improvement in light absorption near the design wavelength is achieved through plasmon-assisted electric field concentration effects. Simulation results show about 50 times light absorption enhancement for 850 nm light due to improved optical signal propagation through the nano-gratings.


Design Of High-Sensitivity Plasmonics-Assisted Gaas Metal-Semiconductor-Metal Photodetectors, Ayman Karar, Narottam Das, Chee Leong Tan, Kamal Alameh, Yong Lee Jan 2010

Design Of High-Sensitivity Plasmonics-Assisted Gaas Metal-Semiconductor-Metal Photodetectors, Ayman Karar, Narottam Das, Chee Leong Tan, Kamal Alameh, Yong Lee

Research outputs pre 2011

In this paper, we use the finite difference timedomain (FDTD) method to optimize the light absorption of an ultrafast plasmonic GaAs metal-semiconductor-metal photodetector (MSM-PD) employing metal nano-gratings. The MSM-PD is optimized geometrically, leading to improved light absorption near the designed wavelength of GaAs through plasmon-assisted electric and magnetic field concentration through a subwavelength aperture. Simulation results show up to 10-times light absorption enhancement at 867 nm due to surface plasmon polaritons (SPPs) propagation through the metal nano-grating, in comparison to conventional MSM-PD.


Absorption Enhancement Of Msm Photodetector Structure With A Plasmonic Double Grating Structure, Chee Leong Tan, Volodymyr V. Lysak, Narottam Das, Ayman Karar, Kamal Alameh, Yong Lee Jan 2010

Absorption Enhancement Of Msm Photodetector Structure With A Plasmonic Double Grating Structure, Chee Leong Tan, Volodymyr V. Lysak, Narottam Das, Ayman Karar, Kamal Alameh, Yong Lee

Research outputs pre 2011

We present finite difference time domain simulation to analyze the optical absorption enhancement of metal-semiconductor-metal photo detectors employing double plasmonic grating structures. Simulation results show that the combination of a subwavelength aperture and double nano-structured metal grating results in up to 25 times enhancement in optical absorption, in comparison to MSM photodetector structures employing only a subwavelength aperture. This improvement of the absorption enhancement is due to the coupling out function of the bottom grating structure which distributes the light to both side of the subwavelength aperture.