Numerical Examination Of The Nonlinear Dynamics Of A Hybrid Acousto-Optic Bragg Cell With Positive Feedback Under Profiled Beam Propagation, 2016 University of Dayton

#### Numerical Examination Of The Nonlinear Dynamics Of A Hybrid Acousto-Optic Bragg Cell With Positive Feedback Under Profiled Beam Propagation, Fares S. Almehmadi, Monish Ranjan Chatterjee

*Monish R. Chatterjee*

In standard weak interaction theory, acousto-optic Bragg analysis typically assumes that the incident light and sound beams are uniform plane waves. Acousto-optic Bragg diffraction with nonuniform profiled input beams is numerically examined under open loop via a transfer function formalism. Unexpected deviations in the first-order diffracted beam from the standard theory are observed for high đť‘„ values. These deviations are significant because the corresponding closed-loop system is sensitive to input amplitudes and initial conditions, and the overall impact on the dynamical behavior has not been studied previously in standard analyses. To explore the effect of such nonuniform output profiles on ...

Numerical Inversion And Assessment Of 2d Laplace Transforms Using The Brancik Algorithm And Its Use In 3d Holography, 2016 University of Dayton

#### Numerical Inversion And Assessment Of 2d Laplace Transforms Using The Brancik Algorithm And Its Use In 3d Holography, Monish Ranjan Chatterjee, Le Feng

*Monish R. Chatterjee*

An analytic examination of 3D holography under a 90Â° recording geometry was carried out earlier in which 2D spatial Laplace transforms were introduced in order to develop transfer functions for the scattered outputs under readout [1,2]. Thereby, the resulting reconstructed output was obtained in the 2D Laplace domain whence the spatial information would be found only by performing a 2D Laplace inversion. Laplace inversion in 2D was attempted by testing a prototype function for which the analytic result was known using two known inversion algorithms, viz., the Brancik and the Abate [2]. The results indicated notable differences in the ...

Numerical Examination Of Acousto-Optic Bragg Interactions For Profiled Lightwaves Using A Transfer Function Formalism, 2016 University of Dayton

#### Numerical Examination Of Acousto-Optic Bragg Interactions For Profiled Lightwaves Using A Transfer Function Formalism, Monish Ranjan Chatterjee, Fares S. Almehmadi

*Monish R. Chatterjee*

Classically, acousto-optic (AO) interactions comprise scattering of photons by energetic phonons into higher and lower orders. Standard weak interaction theory describes diffraction in the Bragg regime as the propagation of a uniform plane wave of light through a uniform plane wave of sound, resulting in the well-known first- and zeroth-order diffraction.

Our preliminary investigation of the nature of wave diffraction and photon scattering from a Bragg cell under intensity feedback with profiled light beams indicates that the diffracted (upshifted photon) light continues to maintain the expected (uniform plane wave) behavior versus the optical phase shift in the cell within a ...

Nonlinear Dynamics Of Bragg-Domain Acousto-Optic Hybrid Feedback For First-Order Scattering Of Profiled Optical Beams, 2016 University of Dayton

#### Nonlinear Dynamics Of Bragg-Domain Acousto-Optic Hybrid Feedback For First-Order Scattering Of Profiled Optical Beams, Monish Ranjan Chatterjee, Fares S. Almehmadi

*Monish R. Chatterjee*

A series of recent studies involving hybrid acousto-optic (AO) scattering in the Bragg domain under first-order feedback have shown the ability of the AO feedback system to encrypt, transmit and decrypt RF information applied via the sound driver. The basic premise of this operation is founded on the chaotic nature of the hybrid Bragg cell under feedback.

Numerical Analysis Of First-Order Acousto-Optic Bragg Diffraction Of Profiled Optical Beams Using Open-Loop Transfer Functions, 2016 University of Dayton

#### Numerical Analysis Of First-Order Acousto-Optic Bragg Diffraction Of Profiled Optical Beams Using Open-Loop Transfer Functions, Monish Ranjan Chatterjee, Fares S. Almehmadi

*Monish R. Chatterjee*

In standard acousto-optic Bragg analysis, the incident light and sound beams are assumed to be uniform plane waves (with constant profiles) leading to the results based on standard weak interaction theory. As a follow-up to earlier work dealing with nonuniform incident optical beams, we revisit the problem of Bragg diffraction under nonuniform profiles, and include Gaussian, third-order Hermiteâ€“Gaussian, and zeroth-order Bessel profiles in our investigation, along with a few others. The first-order diffracted beam is examined (using a transfer function formalism based on angular spectra) under several parametric limits [such as the Kleinâ€“Cook parameter Q, the effective profile ...

Large-Area Object Search And Recovery Using Sector-Based Aerial Acousto-Optic Scanning And Reflection Sensing, 2016 University of Dayton

#### Large-Area Object Search And Recovery Using Sector-Based Aerial Acousto-Optic Scanning And Reflection Sensing, Monish Ranjan Chatterjee, Salaheddeen G. Bugoffa

*Monish R. Chatterjee*

A sector-based angular scanning system intended to identify and spatially locate relatively small objects scattered over a large terrain is described in this paper. The system is modeled as a planar surface on the horizontal (XY) plane, with an acousto-optic Bragg cell on board an unmanned aerial vehicle (UAV) operating in the XZ plane. The Bragg cell is excited by a chirped RF signal with a designed frequency ramp. As the scanning beam reflects off the horizontal surface, a detector placed strategically at a suitable altitude (in the analysis shown to be on board the UAV itself) picks up the ...

Modeling Of Power Spectral Density Of Modified Von Karman Atmospheric Phase Turbulence And Acousto-Optic Chaos Using Scattered Intensity Profiles Over Discrete Time Intervals, 2016 University of Dayton

#### Modeling Of Power Spectral Density Of Modified Von Karman Atmospheric Phase Turbulence And Acousto-Optic Chaos Using Scattered Intensity Profiles Over Discrete Time Intervals, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

*Monish R. Chatterjee*

In recent research, propagation of plane electromagnetic (EM) waves through a turbulent medium with modified von Karman phase characteristics was modeled and numerically simulated using transverse planar apertures representing narrow phase turbulence along the propagation path.

The case for extended turbulence was also studied by repeating the planar phase screens multiple times over the propagation path and incorporating diffractive effects via a split-step algorithm. The goal of the research reported here is to examine two random phenomena: (a) atmospheric turbulence due to von Karman-type phase fluctuations, and (b) chaos generated in an acousto-optic (A-O) Bragg cell under hybrid feedback. The ...

Investigation Of Negative Refractive Index In Reciprocal Chiral Materials, 2016 University of Dayton

#### Investigation Of Negative Refractive Index In Reciprocal Chiral Materials, Monish Ranjan Chatterjee, Partha P. Banerjee, Pradeep R. Anugula

*Monish R. Chatterjee*

It is well known that there exist both natural materials (such as milk or sugar solution) possessing chiral (or handed) properties, as well as an increasing list of man-made materials (such as sodium bromate) that exhibit chirality. One of the principal properties of chirality is that light of any arbitrary polarization, when propagating through a chiral material, splits up into two circular polarizations propagating in different directions. In the past decade or longer, researchers have investigated electromagnetic transverse (plane) wave propagation across a non-chiral/chiral interface, and determined the electromagnetic Fresnel coefficients for such propagation. Traditionally, such coefficients are derived ...

Investigation Of Negative Index In Dispersive, Chiral Materials Via Contra-Propagating Velocities Under Second-Order Dispersion (Gvd), 2016 University of Dayton

#### Investigation Of Negative Index In Dispersive, Chiral Materials Via Contra-Propagating Velocities Under Second-Order Dispersion (Gvd), Monish Ranjan Chatterjee, Tarig A. Algadey

*Monish R. Chatterjee*

Negative refractive index arises typically in metamaterials via multiple routes. One such avenue is the condition where the Poynting vector of the electromagnetic wave is in opposition to the group velocity in the material. An earlier work along this route in a chiral material led to the well-known result of requiring very large (non-realizable) chirality.

Thereafter, a combination of chirality together with first-order dispersion was examined using plane wave electromagnetic analysis. To arrive at the conclusions in that approach, the three wave velocities (energy, group and phase) were derived under first-order dispersion in permittivity, permeability and chirality. Negative index in ...

Information Encryption And Retrieval In Mid-Rf Range Using Acousto-Optic Chaos, 2016 University of Dayton

#### Information Encryption And Retrieval In Mid-Rf Range Using Acousto-Optic Chaos, Monish Ranjan Chatterjee, Abhinay Kundur

*Monish R. Chatterjee*

In recent work, low-frequency AC signal encryption, decryption and retrieval using system-parameter based keys at the receiver stage of an acousto-optic (A-O) Bragg cell under first-order feedback have been demonstrated [1,2]. The corresponding nonlinear dynamics have also been investigated using the Lyapunov exponent and the so-called bifurcation maps [3]. The results were essentially restricted to A-O chaos around 10 KHz, and (baseband) signal bandwidths in the 1-4 KHz range. The results have generally been satisfactory, and parameter tolerances (prior to severe signal distortion at the output) in the Â±5% - Â±10% range have been obtained. Periodic AC waveforms, and a ...

Investigation Of Electronic Holography Using Spice Computer Simulation Experiments, 2016 University of Dayton

#### Investigation Of Electronic Holography Using Spice Computer Simulation Experiments, Monish Ranjan Chatterjee

*Monish R. Chatterjee*

Using SPICE experiments, it has been possible to verify most of the important aspects of electronic holography. The generation and properties of dynamic echoes under different types of nonlinearities have been extensively tested, and some new information has been garnered in the process. The case of pulse and generalized memory echoes has also been tested, and the results have been fairly satisfactory. Most of all, the simplicity with which the intriguing concept of memory echoes has translated into the circuit implementation on SPICE, and the closeness of the results to predicted behavior have been somewhat of a pleasant surprise.

Since ...

Improved Performance Of Analog And Digital Acousto-Optic Modulation With Feedback Under Profiled Beam Propagation For Secure Communication Using Chaos, 2016 University of Dayton

#### Improved Performance Of Analog And Digital Acousto-Optic Modulation With Feedback Under Profiled Beam Propagation For Secure Communication Using Chaos, Fares S. Almehmadi, Monish Ranjan Chatterjee

*Monish R. Chatterjee*

Using intensity feedback, the closed-loop behavior of an acousto-optic hybrid device under profiled beam propagation has been recently shown to exhibit wider chaotic bands potentially leading to an increase in both the dynamic range and sensitivity to key parameters that characterize the encryption. In this work, a detailed examination is carried out vis-Ă -vis the robustness of the encryption/decryption process relative to parameter mismatch for both analog and pulse code modulation signals, and bit error rate (BER) curves are used to examine the impact of additive white noise. The simulations with profiled input beams are shown to produce a stronger ...

Information Encryption, Transmission, And Retrieval Via Chaotic Modulation In A Hybrid Acousto-Optic Bragg Cell Under Profiled Beam Illumination, 2016 University of Dayton

#### Information Encryption, Transmission, And Retrieval Via Chaotic Modulation In A Hybrid Acousto-Optic Bragg Cell Under Profiled Beam Illumination, Monish Ranjan Chatterjee, Fares S. Almehmadi

*Monish R. Chatterjee*

In recent work, the propagation of a profiled optical beam through an open-loop acousto-optic Bragg cell was examined using a transfer function formalism. The device was also studied under closed-loop via intensity feedback, and shown to exhibit more extended chaotic band responses, thereby potentially increasing the dynamic range and parameter sensitivities of any applied signal and the device operation respectively. In this paper, simple low- to mid-RF signals (periodic waveforms and low BW audio) are transmitted through the closed-loop system and the resulting encryption and recovery at the receiver are examined especially from the perspective of overall robustness of the ...

Investigation Of Electromagnetic Velocities And Negative Refraction In A Chiral Metamaterial With Second-Order Material Dispersion Using Spectral Analyses And Dispersive Models, 2016 University of Dayton

#### Investigation Of Electromagnetic Velocities And Negative Refraction In A Chiral Metamaterial With Second-Order Material Dispersion Using Spectral Analyses And Dispersive Models, Monish Ranjan Chatterjee, Tarig A. Algadey

*Monish R. Chatterjee*

In recent years, considerable research has been carried out relative to the electromagnetic (EM) propagation and refraction characteristics in metamaterials with emphasis on the origins of negative refractive index.

Negative refractive index may be introduced in metamaterials via different methods; one such is the condition whereby the Poynting vector of the EM wave is in opposition to the group velocity in the material. Alternatively, negative refractive index also occurs when the group and phase velocities in the medium are in opposition. The latter phenomenon has been extensively investigated in the literature, including recent work involving chiral metamaterials with material dispersion ...

Analysis Of Beam Propagation In 90-Degree Holographic Recording And Readout Using Transfer Functions And Numerical 2-D-Laplace Inversion, 2016 University of Dayton

#### Analysis Of Beam Propagation In 90-Degree Holographic Recording And Readout Using Transfer Functions And Numerical 2-D-Laplace Inversion, Monish Ranjan Chatterjee, Partha P. Banerjee, George Nehmetallah

*Monish R. Chatterjee*

Recently, 2-D-Laplace analysis of recording and readout of edge-holograms was reported. Numerical Laplace inversion was examined for simple test cases. Inversion algorithms are applied to examine beam shaping and distortion in photovoltaic and photorefractive materials.

Design Of Acousto-Optic Chaos Based Secure Free-Space Optical Communication Links, 2016 University of Oklahoma

#### Design Of Acousto-Optic Chaos Based Secure Free-Space Optical Communication Links, Anjan K. Ghosh, Pramode K. Verma, Samuel Cheng, Robert C. Huck, Monish Ranjan Chatterjee, Mohammed A. Al-Saedi

*Monish R. Chatterjee*

We discuss the design of an acousto-optic cell based free space optical communication link where the data beam is made secure through chaos encryption. Using external signal modulation of the diffracted light from a hybrid acousto-optic cell chaos (or directly via incorporation in the sound-cell driver's bias voltage) encryption of data is possible. We have shown numerically that decryption of the encoded data is possible by using an identical acousto-optic system in the receiver.

Diffractive Propagation And Recovery Of Modulated (Including Chaotic) Electromagnetic Waves Through Uniform Atmosphere And Modified Von Karman Phase Turbulence, 2016 University of Dayton

#### Diffractive Propagation And Recovery Of Modulated (Including Chaotic) Electromagnetic Waves Through Uniform Atmosphere And Modified Von Karman Phase Turbulence, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

*Monish R. Chatterjee*

In a parallel approach to recently-used transfer function formalism, a study involving diffraction of modulated electromagnetic (EM) waves through uniform and phase-turbulent atmospheres is reported in this paper. Specifically, the input wave is treated as a modulated optical carrier, represented by use of a sinusoidal phasor with a slowly timevarying envelope. Using phasors and (spatial) Fourier transforms, the complex phasor wave is transmitted across a uniform or turbulent medium using the Kirchhoff-Fresnel integral and the random phase screen. Some preliminary results are presented comparing non-chaotic and chaotic information transmission through turbulence, outlining possible improvement in performance utilizing the robust features ...

Examination Of The Nonlinear Dynamics Of A Chaotic Acousto-Optic Bragg Modulator With Feedback Under Signal Encryption And Decryption, 2016 University of Dayton

#### Examination Of The Nonlinear Dynamics Of A Chaotic Acousto-Optic Bragg Modulator With Feedback Under Signal Encryption And Decryption, Mohammed A. Al-Saedi, Monish Ranjan Chatterjee

*Monish R. Chatterjee*

An acousto-optic Bragg cell with first-order feedback, which exhibits chaotic behavior past the threshold for bistability, was recently examined for possible chaotic encryption and recovery of simple messages (such as low-amplitude periodic signals) applied via the bias input of the sound cell driver. We carry out a thorough examination of the nonlinear dynamics of the Bragg cell under intensity feedback for (i) dc variations of the feedback gain (Î˛Ëś) and the phase shift parameter (Î±^ 0) and (ii) ac variations of Î±^ 0; total under signal encryption, investigating both from two different perspectives: (i) examining chaos in view of the ...

Electronic Simulation Of The Temporal Characteristics Of Photon Memory Echoes And Some Related Applications, 2016 State University of New York at Binghamton

#### Electronic Simulation Of The Temporal Characteristics Of Photon Memory Echoes And Some Related Applications, Yuwen Kuo, Monish Ranjan Chatterjee

*Monish R. Chatterjee*

The characteristics of nonlinear photon memory echoes are investigated by means of SPICE simulations using equivalent resonator ensembles. By developing implicit nonlinear circuit models in the memory echo domain, the triple product formalism of electronic holography, involving correlation and convolution, is tested for the storage and recall of arbitrary signals and/or data bit streams in both time-inverted and nontime-inverted modes. Furthermore, a few specific optical data processing applications are also simulated in which the mixed binary multiplication of two or more binary bit streams is achieved.

Higher order products, optical pattern recognition, and other possible applications are also discussed ...

Emergence Of Negative Index In A Lossy Chiral Metamaterial Under First-Order Material Dispersion, 2016 University of Dayton

#### Emergence Of Negative Index In A Lossy Chiral Metamaterial Under First-Order Material Dispersion, Monish Ranjan Chatterjee, Tarig A. Algadey

*Monish R. Chatterjee*

For a lossless dispersive chiral material, negative index (NIM) occurred only by use of parametric analysis (and not via practical models) to first-order. These findings are re-visited for the lossy problem and the results are compared.