Mrinal Sen - Academia.edu (original) (raw)

Papers by Mrinal Sen

Optical and Quantum Electronics, 2013

This paper presents a novel approach for the determination of resonance frequencies in silica fib... more This paper presents a novel approach for the determination of resonance frequencies in silica fiber using composite susceptibility model and Stimulated Raman Scattering (SRS) gain. The Raman gain coefficient in silica fiber is calculated in terms of composite susceptibility model where resonance frequencies of material are considered. Composite susceptibility is optimized using Genetic Algorithm to match calculated gain with the experimental results and, hence eight resonance frequencies are found.

Journal of Applied Physics

A single-pump optical parametric amplifier (OPA) is modeled using a p-toluene sulfonate (PTS) fil... more A single-pump optical parametric amplifier (OPA) is modeled using a p-toluene sulfonate (PTS) filled silicon-based slotted photonic crystal waveguide (SPCW). The PTS-SPCW has CMOS-process compatibility and offers slow-light enhanced nonlinearity of PTS due to extreme optical confinement in SPCW. The adverse effects of two-photon absorption and free carrier absorption are absent in PTS in the standard optical communication window. The coupled nonlinear Schrödinger’s equations have been modified to analyze the OPA under slow-light propagation. Performances of the OPA are evaluated in both the high- and low- dispersive zones of the structure. The high dispersive zone exhibits high group indices to the operating waves, leading to a high parametric gain ([Formula: see text] dB) and high conversion efficiency ([Formula: see text] dB) utilizing a 350 [Formula: see text] long PTS-SPCW and a pump power of 65 mW. However, this zone degrades the shape of a [Formula: see text] ps pulse due to s...

arXiv: Medical Physics, 2015

Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles.... more Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles. The true prospective of this technology is yet to be explored. In this paper, a simple and economic construction of a sEMG sensor is proposed. These sensors are used to determine the differences in the Electromyography (EMG) signal patterns of different individuals. Signals of several volunteers from different age groups, gender and individual having paralysis have been obtained. The sEMG data acquisition is done using the soundcard of a computer, hence reducing the need of additional hardware. Finally, the data is used to analyse the relationship between electromyography and factors like age, gender and health condition i.e. paralysis.

IEEE Transactions on Instrumentation and Measurement

A novel design of multiple-slotted 1-D photonic crystal nanobeam cavity has been proposed in this... more A novel design of multiple-slotted 1-D photonic crystal nanobeam cavity has been proposed in this article. The design utilizes the benefits of high optical density offered by the narrow slots as well as improved light–matter interaction and, thereby, sensitivity due to the multiple slots. Different design parameters, such as width, separation, and number of slots, and number and sizes of holes, are optimized for achieving better quality factor (QF) and sensitivity simultaneously. A QF and sensitivity using two or three number of slots have been found in the order of <inline-formula> <tex-math notation="LaTeX">$3.2\times 10^{7}$ </tex-math></inline-formula> and 1016 nm/refractive index unit (RIU) or <inline-formula> <tex-math notation="LaTeX">$1.26\times 10^{7}$ </tex-math></inline-formula> and 1049 nm/RIU, respectively. Tolerance of the design for possible random fabrication imperfections has also been evaluated. It depicts that the structure is tolerant up to 20-nm random deviations, with low impact to sensitivity, albeit at a moderate cost to the QF for deviations above 10 nm. Finally, the optimized design has been used in a theoretical study for analyzing the applicability of the sensor in assessing glucose levels in human urine samples. The theoretical results suggest that the proposed design can be utilized for realizing efficient industrial and bimolecular sensors.

Optical and Quantum Electronics, 2022

In this review, a comprehensive summary on photonic crystal based all-optical logic decoder repor... more In this review, a comprehensive summary on photonic crystal based all-optical logic decoder reported in the last decade has been made. The articles reviewed are primarily grouped into two broad tributaries based on linear and nonlinear regimes of optical interactions inside photonic crystal structures. The reasons behind choosing PhC structures are because of their excellent abilities to control and guide the flow of optical signal along with the intense light-matter interaction in sub-wavelength scale, which have been utilized substantially to realize decoder circuits. Each group of the articles has been analysed extensively, and their prospective merits and demerits are discussed in terms of different performance metrics such as operating speed, requirement of power, footprint, contrast ratio between output logic levels etc. The review concludes while focusing on prospective discussions on the issues for further advancements in this field based on different techniques.

2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018

A width-modulated air-slot photonic crystal (PhC) nanocavity is designed and analyzed. A tapered ... more A width-modulated air-slot photonic crystal (PhC) nanocavity is designed and analyzed. A tapered air-slot, instead of a regularly arranged rectangular slot, is used at the center of a W1 PhC waveguide. This is to reduce the vertical radiation loss which occurs at the abrupt termination of a rectangular slot, and also to increase the inline coupling from a waveguide to the cavity. A three dimensional finite difference time domain method is used to calculate the resonant wavelength, quality factor and modal volume of the cavity which are found as 1.559 μm, 3.4×106 and 0.154 μm3 respectively.

Photonic and Phononic Properties of Engineered Nanostructures IX, 2019

An ultra-compact TE-Pass polarization filter has been designed using silicon-on-insulator based W... more An ultra-compact TE-Pass polarization filter has been designed using silicon-on-insulator based W1 Photonic crystal (PhC) slab waveguide structure. The proposed filter has been designed by judicial choice of dimensions of the W1 PhC waveguide, so that it can pass only the TE polarized light and block the TM polarized light. A high extinction ratio ≈34 dB, with nearly ≈1.5 dB insertion loss, has been achieved at wavelength 1550 nm in ≈5 μm long device. The simple structure of the device can be fabricated in single step of lithography with the well-established CMOS fabrication technique.

2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018

A silicon nanocrystal embedded Nonlinear Slotted Photonic Crystal Waveguide (NSPhCW) is proposed ... more A silicon nanocrystal embedded Nonlinear Slotted Photonic Crystal Waveguide (NSPhCW) is proposed to reduce the length of the nonlinear section required in a typical all-optical switching device. Phase-variation of a pulse due to the effect of self-phase modulation and cross-phase modulation has been calculated and analysed under slow-light regime using a modified Nonlinear Schrodinger Equation (NSEs). A 180-degree phase shift is observed in a sub-hundred micrometer length of the NSPhCW even without the effect of XPM. Also, the addition of a control signal increases the change in phase shift more drastically and a same phase shift is attained in a smaller length.

Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles.... more Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles. The true prospective of this technology is yet to be explored. In this paper, we used a simple and economically constructed sEMG sensor. These sensors were used to determine the differences in the Electromyography (EMG) signal patterns for investigating the loss in the muscle strength of a half paralytic person. Signals have been retrieved from the Flexor carpi radialis muscle of both the arms of a half paralytic person. The sEMG data acquisition is done using the soundcard of a computer, hence reducing the need of additional hardware. Finally, the data is used to analyze the relationship between electromyography and loss of strength due to paralysis. Our results clearly show the difference between muscle strength of the two hands, healthy hand and paralytic hand, of the same half paralytic individual.

Journal of the Optical Society of America B, 2021

A completely new model of an all-optical switch (AOS) is proposed using a silicon photonic crysta... more A completely new model of an all-optical switch (AOS) is proposed using a silicon photonic crystal (PhC) slab based nonlinear Mach–Zehnder interferometer (NMZI). Both arms of the NMZI are designed using p-toluene sulfonate (PTS) based slotted PhC waveguides (PTS-SPCWs). Extreme optical confinement in SPCW is used here to intensify optical nonlinearities of PTS. The intensified nonlinearity produces significant phase changes in optical pulses within a small waveguide length, even when the optical power is sufficiently small. One arm of the NMZI is coupled with a control wave to incur additional phase shift compared to the other due to cross-phase modulation, in addition to self-phase modulation, which is a common phenomenon for both. The differential phase shift originates destructive/constructive interference, leading to a successful switching operation of the AOS. Switching characteristics of the AOS are evaluated for a variety of parameters. A typical example shows that the AOS can switch off 12.55 mW probe power with an extinction ratio of ≈50.5dB by applying 5.65 mW control power, while the device footprint is merely 259µm2. The low-power and high-speed operation makes this small footprint AOS device suitable for applications in photonic integrated circuits.

2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018

Design of an ultra-compact all optical 4 channel de-multiplexer is proposed in this work based on... more Design of an ultra-compact all optical 4 channel de-multiplexer is proposed in this work based on a two dimensional photonic crystal (PhC) structure. The PhC is formed using some silicon rods suspended in the air medium, which are arranged in a square lattice in a footprint of 75.24 μm2. The proposed component is designed to de-multiplex the wavelengths 1.31 μm, 1.43 μm, 1.55 μm and 1.7 μm. Simulations are performed using the Plane Wave Expansion (PWE) and the Finite Difference Time Domain (FDTD) methods which exhibit that the device offers a high contrast ratio ∼ 49 dB and a high data rate ∼ 3.8 Tbit/s.

Applied Optics, 2020

A new device architecture has been proposed in this paper implementing the all-optical cascadable... more A new device architecture has been proposed in this paper implementing the all-optical cascadable logic NOR functionality. The device functions based on stimulated Raman scattering (SRS) in silicon nanocrystal embedded slotted photonic crystal waveguide (SPCW). Substantial miniaturizations both in operating power and overall footprint of the device have been achieved owing to the ultrahigh SRS gain of silicon nanocrystal and strong spatio-temporal confinement of the SPCW. Successful operation of the device has been demonstrated at a pulse rate that is as high as 125 Gbps.

Journal of Applied Physics, 2020

A silicon photonic crystal waveguide based design of a highly-compact transverse-magnetic pass po... more A silicon photonic crystal waveguide based design of a highly-compact transverse-magnetic pass polarization filter has been proposed in this paper. The device utilizes both the index guiding and bandgap property simultaneously to realize its operation as a polarizer. Optimizations of different device-parameters, such as the radius of the holes, width, thickness, and length of the waveguide, have been performed for attaining its paramount performance. A small waveguide length, in the order of 5 μm, has shown a high extinction ratio, i.e., 45 dB, at the wavelength of 1550 nm. A uniform bandwidth of %120 nm is observed, beyond the extinction ratio of 40 dB, along with a remarkably low insertion loss, i.e., % 0:6 dB. Investigations are also performed to evaluate performances of the polarizer under possible fabrication disorders, which depicts a sustained performance up to at least a random fabrication disorder of 30 nm. These merits make the polarizer suitable for applications in densely integrable photonic integrated circuits.

Journal of Applied Physics, 2019

Self-organized spatially separated silver 3D dendrites as efficient plasmonic nanostructures for ... more Self-organized spatially separated silver 3D dendrites as efficient plasmonic nanostructures for surface-enhanced Raman spectroscopy applications

Journal of the Optical Society of America B, 2019

A six-channel wavelength-division multiplexing filter is proposed in this paper, based on a two-d... more A six-channel wavelength-division multiplexing filter is proposed in this paper, based on a two-dimensional rods-in-air square-lattice photonic crystal (PhC) slab structure. The plane wave expansion method is applied to compute the band structure of the PhC. Three-dimensional finite-difference time-domain simulation methodology is used to measure and analyze the performance of the filter. Performances for both the 2D and 3D designs of the structure are analyzed. The analyses show that the device is capable of filtering six different wavelengths, i.e., 1310 nm, 1415 nm, 1455 nm, 1550 nm, 1725 nm, and 1770 nm. Owing to its linear optical operation, the device is able to operate at low power and also offers a high data rate in the range of $ \approx 0.9\,\,{\rm Tb/s} ≈0.9Tb/sto≈0.9Tb/s to ≈0.9Tb/sto \approx 4\,\,{\rm Tb/s} ≈4Tb/s.Moreover,thefootprintareaoftheproposeddeviceisontheorderof≈4Tb/s. Moreover, the footprint area of the proposed device is on the order of ≈4Tb/s.Moreover,thefootprintareaoftheproposeddeviceisontheorderof {165}\,\,{{\unicode{x00B5}{\rm m}}^2} $165µm2, which is suitable for high-density integration of photonic circuits.

Transactions of the Institute of Measurement and Control, 2019

Key comparison measurements serve as an ultimate tool of quality assurance of results. Whenever t... more Key comparison measurements serve as an ultimate tool of quality assurance of results. Whenever the inter-comparison results indicate inconsistency, the participating laboratory needs to take the corrective actions. Practically, the systematic errors involved in the measuring system confines the achievable accuracy. Therefore, the corrective action involves either empirically determine the influences afresh or intuitively reassigns these error values. Alternatively, an analytical method based on inter laboratory comparison results is proposed. The novelty of the proposal is considering task-specific errors in the model that is used for the analysis of interlaboratory comparison results. Without accounting the uncertainties of task-specific errors, the analysis grows complicated and even sometimes it is not feasible. To supplement the proposed method, task-specific errors due to the imperfect geometry of ring gauge, practical inability in implementing the measurement, and unattended ...

Superlattices and Microstructures, 2016

In this work, a theoretical model for radial p-n junction microwire array solar cell with pyramid... more In this work, a theoretical model for radial p-n junction microwire array solar cell with pyramidal structures in the space between microwires has been developed. Incorporation of pyramidal structures results in reflection of light, which would otherwise be unused, and illuminates side walls of the microwires. This additional illumination enhances absorption and, hence, efficiency of the whole structure. Efficiency enhancement is analyzed by varying different device parameters e.g., radius and length of each microwire and packing fraction of the structure. Results show that the maximum fractional efficiency enhancement can be obtained as 30% by suitable choice of these parameters.

Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles.... more Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles. The true prospective of this technology is yet to be explored. In this paper, we used a simple and economically constructed sEMG sensor. These sensors were used to determine the differences in the Electromyography (EMG) signal patterns for investigating the loss in the muscle strength of a half paralytic person. Signals have been retrieved from the Flexor carpi radialis muscle of both the arms of a half paralytic person. The sEMG data acquisition is done using the soundcard of a computer, hence reducing the need of additional hardware. Finally, the data is used to analyze the relationship between electromyography and loss of strength due to paralysis. Our results clearly show the difference between muscle strength of the two hands, healthy hand and paralytic hand, of the same half paralytic individual.

2014 International Conference on Devices, Circuits and Communications (ICDCCom), 2014

New design for silicon based integrable coupler/pump-combiner is presented in the paper. The pump... more New design for silicon based integrable coupler/pump-combiner is presented in the paper. The pump-combiner is designed with the view of efficient stimulated Raman scattering/Raman amplification in silicon waveguides. Performances of some couplers with well-known structure are also analyzed in this work. Analysis of the new coupler shows significant improvement in the transmittance performance compared with the well-known structures, discussed in the work.

Journal of the Optical Society of America B, 2018

A new model of an optical parametric amplifier is proposed based on a silicon-slab slotted photon... more A new model of an optical parametric amplifier is proposed based on a silicon-slab slotted photonic crystal waveguide (SPCW). The slot is considered to be filled with silicon nanocrystal material (SiNC/SiO2) having a high Kerr nonlinearity. The extreme optical confinement (spatial and temporal) of the SPCW has enhanced the optical nonlinearity, and thus, a high parametric gain is attained in a small length of the waveguide. Further, for analyses of pulse propagation, the coupled nonlinear Schrodinger’s equations have been modified to incorporate the enhancements in the linear and the nonlinear coefficients due to the slow-light effect. Simulations have been performed on both the high group index region and the low-dispersion regions of the guided band. The simulations on the high group index region, centered at ≈1584 nm, depict a 22.6 dB parametric gain and a 20.9 dB conversion efficiency at a waveguide length of 152 μm, with an effective pump power and peak input signal power of 700 mW and 0.25 Mw, respectively. The pulsating signal, with a pulse width of 5 ps, also experienced a negligible deterioration in its pulse shapes in this length of the SPCW. On the other hand, the simulations on the region of negligible dispersion, centered at 1530 nm, have produced an over 10 dB parametric gain and conversion efficiency through a long range of wavelengths, i.e., 1490–1568 nm, which covers half of the S-band and the complete C-band of the optical communication windows. The significant gain at a micrometer scale length of the waveguide is expected to advance the possibility of on-chip integration of a high-speed all-optical amplifier in photonic integrated circuits.

Optical and Quantum Electronics, 2013

This paper presents a novel approach for the determination of resonance frequencies in silica fib... more This paper presents a novel approach for the determination of resonance frequencies in silica fiber using composite susceptibility model and Stimulated Raman Scattering (SRS) gain. The Raman gain coefficient in silica fiber is calculated in terms of composite susceptibility model where resonance frequencies of material are considered. Composite susceptibility is optimized using Genetic Algorithm to match calculated gain with the experimental results and, hence eight resonance frequencies are found.

Journal of Applied Physics

A single-pump optical parametric amplifier (OPA) is modeled using a p-toluene sulfonate (PTS) fil... more A single-pump optical parametric amplifier (OPA) is modeled using a p-toluene sulfonate (PTS) filled silicon-based slotted photonic crystal waveguide (SPCW). The PTS-SPCW has CMOS-process compatibility and offers slow-light enhanced nonlinearity of PTS due to extreme optical confinement in SPCW. The adverse effects of two-photon absorption and free carrier absorption are absent in PTS in the standard optical communication window. The coupled nonlinear Schrödinger’s equations have been modified to analyze the OPA under slow-light propagation. Performances of the OPA are evaluated in both the high- and low- dispersive zones of the structure. The high dispersive zone exhibits high group indices to the operating waves, leading to a high parametric gain ([Formula: see text] dB) and high conversion efficiency ([Formula: see text] dB) utilizing a 350 [Formula: see text] long PTS-SPCW and a pump power of 65 mW. However, this zone degrades the shape of a [Formula: see text] ps pulse due to s...

arXiv: Medical Physics, 2015

Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles.... more Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles. The true prospective of this technology is yet to be explored. In this paper, a simple and economic construction of a sEMG sensor is proposed. These sensors are used to determine the differences in the Electromyography (EMG) signal patterns of different individuals. Signals of several volunteers from different age groups, gender and individual having paralysis have been obtained. The sEMG data acquisition is done using the soundcard of a computer, hence reducing the need of additional hardware. Finally, the data is used to analyse the relationship between electromyography and factors like age, gender and health condition i.e. paralysis.

IEEE Transactions on Instrumentation and Measurement

A novel design of multiple-slotted 1-D photonic crystal nanobeam cavity has been proposed in this... more A novel design of multiple-slotted 1-D photonic crystal nanobeam cavity has been proposed in this article. The design utilizes the benefits of high optical density offered by the narrow slots as well as improved light–matter interaction and, thereby, sensitivity due to the multiple slots. Different design parameters, such as width, separation, and number of slots, and number and sizes of holes, are optimized for achieving better quality factor (QF) and sensitivity simultaneously. A QF and sensitivity using two or three number of slots have been found in the order of <inline-formula> <tex-math notation="LaTeX">$3.2\times 10^{7}$ </tex-math></inline-formula> and 1016 nm/refractive index unit (RIU) or <inline-formula> <tex-math notation="LaTeX">$1.26\times 10^{7}$ </tex-math></inline-formula> and 1049 nm/RIU, respectively. Tolerance of the design for possible random fabrication imperfections has also been evaluated. It depicts that the structure is tolerant up to 20-nm random deviations, with low impact to sensitivity, albeit at a moderate cost to the QF for deviations above 10 nm. Finally, the optimized design has been used in a theoretical study for analyzing the applicability of the sensor in assessing glucose levels in human urine samples. The theoretical results suggest that the proposed design can be utilized for realizing efficient industrial and bimolecular sensors.

Optical and Quantum Electronics, 2022

In this review, a comprehensive summary on photonic crystal based all-optical logic decoder repor... more In this review, a comprehensive summary on photonic crystal based all-optical logic decoder reported in the last decade has been made. The articles reviewed are primarily grouped into two broad tributaries based on linear and nonlinear regimes of optical interactions inside photonic crystal structures. The reasons behind choosing PhC structures are because of their excellent abilities to control and guide the flow of optical signal along with the intense light-matter interaction in sub-wavelength scale, which have been utilized substantially to realize decoder circuits. Each group of the articles has been analysed extensively, and their prospective merits and demerits are discussed in terms of different performance metrics such as operating speed, requirement of power, footprint, contrast ratio between output logic levels etc. The review concludes while focusing on prospective discussions on the issues for further advancements in this field based on different techniques.

2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018

A width-modulated air-slot photonic crystal (PhC) nanocavity is designed and analyzed. A tapered ... more A width-modulated air-slot photonic crystal (PhC) nanocavity is designed and analyzed. A tapered air-slot, instead of a regularly arranged rectangular slot, is used at the center of a W1 PhC waveguide. This is to reduce the vertical radiation loss which occurs at the abrupt termination of a rectangular slot, and also to increase the inline coupling from a waveguide to the cavity. A three dimensional finite difference time domain method is used to calculate the resonant wavelength, quality factor and modal volume of the cavity which are found as 1.559 μm, 3.4×106 and 0.154 μm3 respectively.

Photonic and Phononic Properties of Engineered Nanostructures IX, 2019

An ultra-compact TE-Pass polarization filter has been designed using silicon-on-insulator based W... more An ultra-compact TE-Pass polarization filter has been designed using silicon-on-insulator based W1 Photonic crystal (PhC) slab waveguide structure. The proposed filter has been designed by judicial choice of dimensions of the W1 PhC waveguide, so that it can pass only the TE polarized light and block the TM polarized light. A high extinction ratio ≈34 dB, with nearly ≈1.5 dB insertion loss, has been achieved at wavelength 1550 nm in ≈5 μm long device. The simple structure of the device can be fabricated in single step of lithography with the well-established CMOS fabrication technique.

2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018

A silicon nanocrystal embedded Nonlinear Slotted Photonic Crystal Waveguide (NSPhCW) is proposed ... more A silicon nanocrystal embedded Nonlinear Slotted Photonic Crystal Waveguide (NSPhCW) is proposed to reduce the length of the nonlinear section required in a typical all-optical switching device. Phase-variation of a pulse due to the effect of self-phase modulation and cross-phase modulation has been calculated and analysed under slow-light regime using a modified Nonlinear Schrodinger Equation (NSEs). A 180-degree phase shift is observed in a sub-hundred micrometer length of the NSPhCW even without the effect of XPM. Also, the addition of a control signal increases the change in phase shift more drastically and a same phase shift is attained in a smaller length.

Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles.... more Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles. The true prospective of this technology is yet to be explored. In this paper, we used a simple and economically constructed sEMG sensor. These sensors were used to determine the differences in the Electromyography (EMG) signal patterns for investigating the loss in the muscle strength of a half paralytic person. Signals have been retrieved from the Flexor carpi radialis muscle of both the arms of a half paralytic person. The sEMG data acquisition is done using the soundcard of a computer, hence reducing the need of additional hardware. Finally, the data is used to analyze the relationship between electromyography and loss of strength due to paralysis. Our results clearly show the difference between muscle strength of the two hands, healthy hand and paralytic hand, of the same half paralytic individual.

Journal of the Optical Society of America B, 2021

A completely new model of an all-optical switch (AOS) is proposed using a silicon photonic crysta... more A completely new model of an all-optical switch (AOS) is proposed using a silicon photonic crystal (PhC) slab based nonlinear Mach–Zehnder interferometer (NMZI). Both arms of the NMZI are designed using p-toluene sulfonate (PTS) based slotted PhC waveguides (PTS-SPCWs). Extreme optical confinement in SPCW is used here to intensify optical nonlinearities of PTS. The intensified nonlinearity produces significant phase changes in optical pulses within a small waveguide length, even when the optical power is sufficiently small. One arm of the NMZI is coupled with a control wave to incur additional phase shift compared to the other due to cross-phase modulation, in addition to self-phase modulation, which is a common phenomenon for both. The differential phase shift originates destructive/constructive interference, leading to a successful switching operation of the AOS. Switching characteristics of the AOS are evaluated for a variety of parameters. A typical example shows that the AOS can switch off 12.55 mW probe power with an extinction ratio of ≈50.5dB by applying 5.65 mW control power, while the device footprint is merely 259µm2. The low-power and high-speed operation makes this small footprint AOS device suitable for applications in photonic integrated circuits.

2018 3rd International Conference on Microwave and Photonics (ICMAP), 2018

Design of an ultra-compact all optical 4 channel de-multiplexer is proposed in this work based on... more Design of an ultra-compact all optical 4 channel de-multiplexer is proposed in this work based on a two dimensional photonic crystal (PhC) structure. The PhC is formed using some silicon rods suspended in the air medium, which are arranged in a square lattice in a footprint of 75.24 μm2. The proposed component is designed to de-multiplex the wavelengths 1.31 μm, 1.43 μm, 1.55 μm and 1.7 μm. Simulations are performed using the Plane Wave Expansion (PWE) and the Finite Difference Time Domain (FDTD) methods which exhibit that the device offers a high contrast ratio ∼ 49 dB and a high data rate ∼ 3.8 Tbit/s.

Applied Optics, 2020

A new device architecture has been proposed in this paper implementing the all-optical cascadable... more A new device architecture has been proposed in this paper implementing the all-optical cascadable logic NOR functionality. The device functions based on stimulated Raman scattering (SRS) in silicon nanocrystal embedded slotted photonic crystal waveguide (SPCW). Substantial miniaturizations both in operating power and overall footprint of the device have been achieved owing to the ultrahigh SRS gain of silicon nanocrystal and strong spatio-temporal confinement of the SPCW. Successful operation of the device has been demonstrated at a pulse rate that is as high as 125 Gbps.

Journal of Applied Physics, 2020

A silicon photonic crystal waveguide based design of a highly-compact transverse-magnetic pass po... more A silicon photonic crystal waveguide based design of a highly-compact transverse-magnetic pass polarization filter has been proposed in this paper. The device utilizes both the index guiding and bandgap property simultaneously to realize its operation as a polarizer. Optimizations of different device-parameters, such as the radius of the holes, width, thickness, and length of the waveguide, have been performed for attaining its paramount performance. A small waveguide length, in the order of 5 μm, has shown a high extinction ratio, i.e., 45 dB, at the wavelength of 1550 nm. A uniform bandwidth of %120 nm is observed, beyond the extinction ratio of 40 dB, along with a remarkably low insertion loss, i.e., % 0:6 dB. Investigations are also performed to evaluate performances of the polarizer under possible fabrication disorders, which depicts a sustained performance up to at least a random fabrication disorder of 30 nm. These merits make the polarizer suitable for applications in densely integrable photonic integrated circuits.

Journal of Applied Physics, 2019

Self-organized spatially separated silver 3D dendrites as efficient plasmonic nanostructures for ... more Self-organized spatially separated silver 3D dendrites as efficient plasmonic nanostructures for surface-enhanced Raman spectroscopy applications

Journal of the Optical Society of America B, 2019

A six-channel wavelength-division multiplexing filter is proposed in this paper, based on a two-d... more A six-channel wavelength-division multiplexing filter is proposed in this paper, based on a two-dimensional rods-in-air square-lattice photonic crystal (PhC) slab structure. The plane wave expansion method is applied to compute the band structure of the PhC. Three-dimensional finite-difference time-domain simulation methodology is used to measure and analyze the performance of the filter. Performances for both the 2D and 3D designs of the structure are analyzed. The analyses show that the device is capable of filtering six different wavelengths, i.e., 1310 nm, 1415 nm, 1455 nm, 1550 nm, 1725 nm, and 1770 nm. Owing to its linear optical operation, the device is able to operate at low power and also offers a high data rate in the range of $ \approx 0.9\,\,{\rm Tb/s} ≈0.9Tb/sto≈0.9Tb/s to ≈0.9Tb/sto \approx 4\,\,{\rm Tb/s} ≈4Tb/s.Moreover,thefootprintareaoftheproposeddeviceisontheorderof≈4Tb/s. Moreover, the footprint area of the proposed device is on the order of ≈4Tb/s.Moreover,thefootprintareaoftheproposeddeviceisontheorderof {165}\,\,{{\unicode{x00B5}{\rm m}}^2} $165µm2, which is suitable for high-density integration of photonic circuits.

Transactions of the Institute of Measurement and Control, 2019

Key comparison measurements serve as an ultimate tool of quality assurance of results. Whenever t... more Key comparison measurements serve as an ultimate tool of quality assurance of results. Whenever the inter-comparison results indicate inconsistency, the participating laboratory needs to take the corrective actions. Practically, the systematic errors involved in the measuring system confines the achievable accuracy. Therefore, the corrective action involves either empirically determine the influences afresh or intuitively reassigns these error values. Alternatively, an analytical method based on inter laboratory comparison results is proposed. The novelty of the proposal is considering task-specific errors in the model that is used for the analysis of interlaboratory comparison results. Without accounting the uncertainties of task-specific errors, the analysis grows complicated and even sometimes it is not feasible. To supplement the proposed method, task-specific errors due to the imperfect geometry of ring gauge, practical inability in implementing the measurement, and unattended ...

Superlattices and Microstructures, 2016

In this work, a theoretical model for radial p-n junction microwire array solar cell with pyramid... more In this work, a theoretical model for radial p-n junction microwire array solar cell with pyramidal structures in the space between microwires has been developed. Incorporation of pyramidal structures results in reflection of light, which would otherwise be unused, and illuminates side walls of the microwires. This additional illumination enhances absorption and, hence, efficiency of the whole structure. Efficiency enhancement is analyzed by varying different device parameters e.g., radius and length of each microwire and packing fraction of the structure. Results show that the maximum fractional efficiency enhancement can be obtained as 30% by suitable choice of these parameters.

Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles.... more Surface Electromyography (sEMG) is a technology to measure the bio-potentials across the muscles. The true prospective of this technology is yet to be explored. In this paper, we used a simple and economically constructed sEMG sensor. These sensors were used to determine the differences in the Electromyography (EMG) signal patterns for investigating the loss in the muscle strength of a half paralytic person. Signals have been retrieved from the Flexor carpi radialis muscle of both the arms of a half paralytic person. The sEMG data acquisition is done using the soundcard of a computer, hence reducing the need of additional hardware. Finally, the data is used to analyze the relationship between electromyography and loss of strength due to paralysis. Our results clearly show the difference between muscle strength of the two hands, healthy hand and paralytic hand, of the same half paralytic individual.

2014 International Conference on Devices, Circuits and Communications (ICDCCom), 2014

New design for silicon based integrable coupler/pump-combiner is presented in the paper. The pump... more New design for silicon based integrable coupler/pump-combiner is presented in the paper. The pump-combiner is designed with the view of efficient stimulated Raman scattering/Raman amplification in silicon waveguides. Performances of some couplers with well-known structure are also analyzed in this work. Analysis of the new coupler shows significant improvement in the transmittance performance compared with the well-known structures, discussed in the work.

Journal of the Optical Society of America B, 2018

A new model of an optical parametric amplifier is proposed based on a silicon-slab slotted photon... more A new model of an optical parametric amplifier is proposed based on a silicon-slab slotted photonic crystal waveguide (SPCW). The slot is considered to be filled with silicon nanocrystal material (SiNC/SiO2) having a high Kerr nonlinearity. The extreme optical confinement (spatial and temporal) of the SPCW has enhanced the optical nonlinearity, and thus, a high parametric gain is attained in a small length of the waveguide. Further, for analyses of pulse propagation, the coupled nonlinear Schrodinger’s equations have been modified to incorporate the enhancements in the linear and the nonlinear coefficients due to the slow-light effect. Simulations have been performed on both the high group index region and the low-dispersion regions of the guided band. The simulations on the high group index region, centered at ≈1584 nm, depict a 22.6 dB parametric gain and a 20.9 dB conversion efficiency at a waveguide length of 152 μm, with an effective pump power and peak input signal power of 700 mW and 0.25 Mw, respectively. The pulsating signal, with a pulse width of 5 ps, also experienced a negligible deterioration in its pulse shapes in this length of the SPCW. On the other hand, the simulations on the region of negligible dispersion, centered at 1530 nm, have produced an over 10 dB parametric gain and conversion efficiency through a long range of wavelengths, i.e., 1490–1568 nm, which covers half of the S-band and the complete C-band of the optical communication windows. The significant gain at a micrometer scale length of the waveguide is expected to advance the possibility of on-chip integration of a high-speed all-optical amplifier in photonic integrated circuits.