We present a whispering-gallery-mode resonance-enhanced microwave-detected photoconductivity-deca... more We present a whispering-gallery-mode resonance-enhanced microwave-detected photoconductivity-decay method for contactless measurement of recombination lifetime in highresistivity semiconductor layers. We applied the method to undoped Silicon wafers of high resistivity at 5 and 30 kOhm*cm and measured the conductivity relaxation times of 10 and 14 microseconds, respectively. In wafers being considered, they are supposed to be defined by the electron-hole diffusion from the bulk to the wafer surfaces.
2015 9th European Conference on Antennas and Propagation (EuCAP), 2015
We analyze the interplay of two different types of electromagnetic behavior demonstrated by a 2-D... more We analyze the interplay of two different types of electromagnetic behavior demonstrated by a 2-D dielectric prism: Geometrical Optics and resonance. As it is shown, the first is responsible, for instance, for enhanced reflection from an isosceles 90-degree prism of arbitrary epsilon and size, if illuminated from the base. The second is responsible for the peaks in the total scattering and absorption cross-sections (RCS) at the natural-mode frequencies. The numerical model is based on Nystrom discretization of Muller-type integral equations that provides guarantied convergence.
2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2018
This paper describes our theoretical and experimental investigation on light scattering from indi... more This paper describes our theoretical and experimental investigation on light scattering from individual murine red blood cells (RBCs). Based on measured cell morphologies at different ionic strength and osmolarity conditions, we simulated the light scattering characteristics of the cells by using the Muller boundary integral equation (MBIE) method. The calculated cross section values showed good agreement with our experimental data obtained with conventional and imaging-based flow cytometries.
The electromagnetic 2-D scattering from a single biological cell is analyzed by using Muller boun... more The electromagnetic 2-D scattering from a single biological cell is analyzed by using Muller boundary integral equation (MBIE) method. The accuracy and smoothness of the solution are improved by applying Nystrom-type discretization. We present numerical results on a single biological cell during the different major phases of mitosis. The simulations show that the cell shape, as well as the cell orientation, have a large influence on the scattering properties of biological cell models.
We present experimental investigation of light-controlled photonics-enhanced quasi-optical mm-wav... more We present experimental investigation of light-controlled photonics-enhanced quasi-optical mm-wave beam switch operating at a resonant frequency in the mm-wave band of 75 to 110 GHz. The switch is implemented as a Bragg structure with a resonant layer of high-resistivity silicon that creates a narrow transmission peak within the mm-wave propagation gap. The peak amplitude is sensitive to the intensity of light pulses illuminating the structure. When using a silicon wafer of 30 KOhm · cm resistivity and light pulses created by a 400W LED-array light source, we achieved mm-wave transmission peak modulation exceeding 15 dB.
We present a whispering-gallery-mode resonance-enhanced microwave-detected photoconductivity-deca... more We present a whispering-gallery-mode resonance-enhanced microwave-detected photoconductivity-decay method for contactless measurement of recombination lifetime in highresistivity semiconductor layers. We applied the method to undoped Silicon wafers of high resistivity at 5 and 30 kOhm*cm and measured the conductivity relaxation times of 10 and 14 microseconds, respectively. In wafers being considered, they are supposed to be defined by the electron-hole diffusion from the bulk to the wafer surfaces.
2015 9th European Conference on Antennas and Propagation (EuCAP), 2015
We analyze the interplay of two different types of electromagnetic behavior demonstrated by a 2-D... more We analyze the interplay of two different types of electromagnetic behavior demonstrated by a 2-D dielectric prism: Geometrical Optics and resonance. As it is shown, the first is responsible, for instance, for enhanced reflection from an isosceles 90-degree prism of arbitrary epsilon and size, if illuminated from the base. The second is responsible for the peaks in the total scattering and absorption cross-sections (RCS) at the natural-mode frequencies. The numerical model is based on Nystrom discretization of Muller-type integral equations that provides guarantied convergence.
2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2018
This paper describes our theoretical and experimental investigation on light scattering from indi... more This paper describes our theoretical and experimental investigation on light scattering from individual murine red blood cells (RBCs). Based on measured cell morphologies at different ionic strength and osmolarity conditions, we simulated the light scattering characteristics of the cells by using the Muller boundary integral equation (MBIE) method. The calculated cross section values showed good agreement with our experimental data obtained with conventional and imaging-based flow cytometries.
The electromagnetic 2-D scattering from a single biological cell is analyzed by using Muller boun... more The electromagnetic 2-D scattering from a single biological cell is analyzed by using Muller boundary integral equation (MBIE) method. The accuracy and smoothness of the solution are improved by applying Nystrom-type discretization. We present numerical results on a single biological cell during the different major phases of mitosis. The simulations show that the cell shape, as well as the cell orientation, have a large influence on the scattering properties of biological cell models.
We present experimental investigation of light-controlled photonics-enhanced quasi-optical mm-wav... more We present experimental investigation of light-controlled photonics-enhanced quasi-optical mm-wave beam switch operating at a resonant frequency in the mm-wave band of 75 to 110 GHz. The switch is implemented as a Bragg structure with a resonant layer of high-resistivity silicon that creates a narrow transmission peak within the mm-wave propagation gap. The peak amplitude is sensitive to the intensity of light pulses illuminating the structure. When using a silicon wafer of 30 KOhm · cm resistivity and light pulses created by a 400W LED-array light source, we achieved mm-wave transmission peak modulation exceeding 15 dB.
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Papers by Ayhan Altintas