The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Kent D. Choquette - One of the best experts on this subject based on the ideXlab platform.
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mode engineering in linear coherently coupled vertical cavity surface emitting Laser Arrays
IEEE Journal of Selected Topics in Quantum Electronics, 2019Co-Authors: Bradley J. Thompson, Stewart T. M. Fryslie, Zihe Gao, Kent D. ChoquetteAbstract:The supermode tuning of coherent 3 × 1 vertical-cavity surface-emitting Laser Arrays are characterized and simulated. The array elements are resonantly tuned to achieve coherent operation using selective current injection. Depending on the electrical bias, multiple coherent supermodes are observed above threshold. An effective index model is developed to account for the variable current injection and to simulate the supermodes of the linear array. Agreement between experimental near-field and far-field coherent modes and our model simulations are found both at and above lasing threshold.
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Digital Modulation of Coherently-Coupled $2\times1$ Vertical-Cavity Surface-Emitting Laser Arrays
IEEE Photonics Technology Letters, 2019Co-Authors: Harshil Dave, Stewart T. M. Fryslie, Bradley J. Thompson, Peicheng Liao, Alan E. Willner, Kent D. ChoquetteAbstract:We experimentally demonstrated enhanced digital modulation of coherently coupled vertical-cavity surface-emitting Laser Arrays. Mutually coherent behavior of $2\times 1$ proton-implanted index-confined photonic crystal vertical-cavity phased Laser Arrays is characterized using a novel digital modulation scheme. Far-field interference fringe visibility is used to estimate the degree of coherence between two coherently coupled Laser cavities, and a visibility map is created to visualize the dependence of Laser array coherence on the injection current bias. The visibility map indicates that a dual-channel in-phase modulation scheme can preserve the Laser array in mutual coherence while under digital modulation. Experimentally, the high-speed digital modulation signal up to 36 Gb/s is supplied to both Laser elements simultaneously. The resulting eye diagram is shown to be improved under coherent-coupling conditions.
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rate equation analysis and non hermiticity in coupled semiconductor Laser Arrays
Journal of Applied Physics, 2018Co-Authors: Zihe Gao, Matthew T Johnson, Kent D. ChoquetteAbstract:Optically coupled semiconductor Laser Arrays are described by coupled rate equations. The coupled mode equations and carrier densities are included in the analysis, which inherently incorporate the carrier-induced nonlinearities including gain saturation and amplitude-phase coupling. We solve the steady-state coupled rate equations and consider the cavity frequency detuning and the individual Laser pump rates as the experimentally controlled variables. We show that the carrier-induced nonlinearities play a critical role in the mode control, and we identify gain contrast induced by cavity frequency detuning as a unique mechanism for mode control. Photon-mediated energy transfer between cavities is also discussed. Parity-time symmetry and exceptional points in this system are studied. Unbroken parity-time symmetry can be achieved by judiciously combining cavity detuning and unequal pump rates, while broken symmetry lies on the boundary of the optical locking region. Exceptional points are identified at the ...
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rate equation analysis and non hermiticity in coupled semiconductor Laser Arrays
arXiv: Optics, 2018Co-Authors: Zihe Gao, Matthew T Johnson, Kent D. ChoquetteAbstract:Optically-coupled semiconductor Laser Arrays are described by coupled rate equations. The coupled mode equations and carrier densities are included in the analysis, which inherently incorporate the carrier-induced nonlinearities including spatial hole burning and amplitude-phase coupling. We solve the steady-state coupled rate equations and consider the cavity frequency detuning and the individual Laser pump rates as the experimentally controlled variables. We show that the carrier-induced nonlinearities play a critical role in the mode control, and we identify gain contrast induced by cavity frequency detuning as a unique mechanism for mode control. Photon-mediated energy transfer between cavities is also discussed. Parity-time symmetry and exceptional points in this system are studied. Unbroken parity-time symmetry can be achieved by judiciously combining cavity detuning and unequal pump rates, while broken symmetry lies on the boundary of the optical locking region. Exceptional points are identified at the intersect between broken and unbroken parity-time symmetry.
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Non-Hermiticity in Weakly Coupled Semiconductor Laser Arrays
Conference on Lasers and Electro-Optics, 2018Co-Authors: Zihe Gao, Harshil Dave, Bradley J. Thompson, Matthew T Johnson, Kent D. ChoquetteAbstract:Coupled semiconductor Laser Arrays are naturally non-Hermitian optical systems. We show that in a weakly coupled semiconductor Laser array, the control for gain/loss is dominated by the nonlinearities, rather than simply following the pump profile.
Dominic F. Siriani - One of the best experts on this subject based on the ideXlab platform.
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coherence in multielement phased vertical cavity surface emitting Laser Arrays using resonance tuning
IEEE Photonics Journal, 2017Co-Authors: Bradley J. Thompson, Stewart T. M. Fryslie, Dominic F. Siriani, Matthew T Johnson, Zihe Gao, Kent D. ChoquetteAbstract:We show that optical coupling can be achieved reproducibly and with high yield by resonance tuning the elements of substrate-emitting and top-emitting vertical-cavity surface-emitting Laser Arrays. The resonance tuning is enabled by electrical isolation of the lasing elements in the array, which in this paper is done by post fabrication processing. Prior to electrical isolation, the Laser Arrays exhibit incoherent optical properties. Using resonance tuning, both in-phase and out-of-phase coherent modes are observed.
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37 ghz modulation via resonance tuning in single mode coherent vertical cavity Laser Arrays
IEEE Photonics Technology Letters, 2015Co-Authors: Stewart T. M. Fryslie, Dominic F. Siriani, Matthew T Johnson, Meng Peun Tan Siriani, Kent D. ChoquetteAbstract:We show a significant improvement of modulation bandwidth from $2\times 1$ photonic crystal vertical-cavity surface-emitting Laser Arrays. Control of injection bias conditions to array elements enables resonance tuning of each element with variation of the phase relation and coherence of the array, resulting in the ability to tailor the modulation response. A bandwidth of 37 GHz is obtained under highly single-mode coherent operation with narrow spectral width and increased output power while the Laser array is biased at low current density. Lasers with such performance characteristics may greatly enhance high-rate data transfer in computer server, data center, and supercomputer applications with potentially long device lifetime.
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beam steering via resonance detuning in coherently coupled vertical cavity Laser Arrays
Applied Physics Letters, 2013Co-Authors: Matthew T Johnson, Dominic F. Siriani, Michael Renne Ty Tan, Kent D. ChoquetteAbstract:Coherently coupled vertical-cavity surface-emitting Laser Arrays offer unique advantages for nonmechanical beam steering applications. We have applied dynamic coupled mode theory to show that the observed temporal phase shift between vertical-cavity surface-emitting array elements is caused by the detuning of their resonant wavelengths. Hence, a complete theoretical connection between the differential current injection into array elements and the beam steering direction has been established. It is found to be a fundamentally unique beam-steering mechanism with distinct advantages in efficiency, compactness, speed, and phase-sensitivity to current.
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high speed beam steering with phased vertical cavity Laser Arrays
IEEE Journal of Selected Topics in Quantum Electronics, 2013Co-Authors: Matthew T Johnson, Dominic F. Siriani, Michael Renne Ty Tan, Kent D. ChoquetteAbstract:We demonstrate electronic beam steering using phased vertical cavity Laser Arrays at record high speed (1.4·108 deg/s) and sensitivity to current (1.2 deg/100 μA). The relative phase and coherence between the array elements are extracted with a Fraunhoffer propagation method. The spatially resolved spectrum and beam steering dynamics are also analyzed. The thermo-optic effect is found to dominate the phase-shifting mechanism at lower speed steering, while the electronic variation in index dominates at higher speeds (≥10 MHz).
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In-phase antiguided bottom-emitting vertical cavity Laser Arrays
Electronics Letters, 2013Co-Authors: Matthew T Johnson, Dominic F. Siriani, Paul O. Leisher, Kent D. ChoquetteAbstract:In-phase emission from a bottom-emitting, coherently coupled, vertical cavity surface-emitting Laser array is demonstrated for the first time. Various array geometries are examined. An antiguided index profile is used to obtain the preferred on-axis far-field peak from a 2 × 1 array up to 0.9 mW, representing a critical step towards coherent, high-brightness two-dimensional Laser Arrays.
Stewart T. M. Fryslie - One of the best experts on this subject based on the ideXlab platform.
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mode engineering in linear coherently coupled vertical cavity surface emitting Laser Arrays
IEEE Journal of Selected Topics in Quantum Electronics, 2019Co-Authors: Bradley J. Thompson, Stewart T. M. Fryslie, Zihe Gao, Kent D. ChoquetteAbstract:The supermode tuning of coherent 3 × 1 vertical-cavity surface-emitting Laser Arrays are characterized and simulated. The array elements are resonantly tuned to achieve coherent operation using selective current injection. Depending on the electrical bias, multiple coherent supermodes are observed above threshold. An effective index model is developed to account for the variable current injection and to simulate the supermodes of the linear array. Agreement between experimental near-field and far-field coherent modes and our model simulations are found both at and above lasing threshold.
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Digital Modulation of Coherently-Coupled $2\times1$ Vertical-Cavity Surface-Emitting Laser Arrays
IEEE Photonics Technology Letters, 2019Co-Authors: Harshil Dave, Stewart T. M. Fryslie, Bradley J. Thompson, Peicheng Liao, Alan E. Willner, Kent D. ChoquetteAbstract:We experimentally demonstrated enhanced digital modulation of coherently coupled vertical-cavity surface-emitting Laser Arrays. Mutually coherent behavior of $2\times 1$ proton-implanted index-confined photonic crystal vertical-cavity phased Laser Arrays is characterized using a novel digital modulation scheme. Far-field interference fringe visibility is used to estimate the degree of coherence between two coherently coupled Laser cavities, and a visibility map is created to visualize the dependence of Laser array coherence on the injection current bias. The visibility map indicates that a dual-channel in-phase modulation scheme can preserve the Laser array in mutual coherence while under digital modulation. Experimentally, the high-speed digital modulation signal up to 36 Gb/s is supplied to both Laser elements simultaneously. The resulting eye diagram is shown to be improved under coherent-coupling conditions.
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modulation of coherently coupled phased photonic crystal vertical cavity Laser Arrays
IEEE Journal of Selected Topics in Quantum Electronics, 2017Co-Authors: Stewart T. M. Fryslie, Harshil Dave, Bradley J. Thompson, Katherine Lakomy, Patrick J Decker, David K Mcelfresh, Jose E Schuttaine, Kent D. ChoquetteAbstract:The modulation properties of two-element photonic crystal ion-implanted coherently coupled vertical cavity surface emitting Laser Arrays emitting at 850 nm are reported. Single mode emission into either the in-phase or out-of-phase supermode and significant modulation bandwidth enhancement are obtained for both operating conditions. We model our device as a monolithically integrated, mutually optically injection-locked Laser system and show that the phase detuning and injection ratio between array elements are critical parameters influencing modulation bandwidth. Comparison of our experimental measurements to our model is consistent with mutual injection locking. Modulation bandwidth greater than 30 GHz and up to 37 GHz is consistently found for several array designs. We show the modulation response can be tailored for different applications.
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coherence in multielement phased vertical cavity surface emitting Laser Arrays using resonance tuning
IEEE Photonics Journal, 2017Co-Authors: Bradley J. Thompson, Stewart T. M. Fryslie, Dominic F. Siriani, Matthew T Johnson, Zihe Gao, Kent D. ChoquetteAbstract:We show that optical coupling can be achieved reproducibly and with high yield by resonance tuning the elements of substrate-emitting and top-emitting vertical-cavity surface-emitting Laser Arrays. The resonance tuning is enabled by electrical isolation of the lasing elements in the array, which in this paper is done by post fabrication processing. Prior to electrical isolation, the Laser Arrays exhibit incoherent optical properties. Using resonance tuning, both in-phase and out-of-phase coherent modes are observed.
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parity time symmetry in coherently coupled vertical cavity Laser Arrays
Optica, 2017Co-Authors: Zihe Gao, Stewart T. M. Fryslie, Bradley J. Thompson, Scott P Carney, Kent D. ChoquetteAbstract:We report parity-time (PT) symmetry breaking in electrically injected, coherently coupled, vertical cavity surface emitting Laser Arrays. We predict beam steering, mode evolution, and mode hopping as consequences of the non-Hermiticity of the array, analyzed by the temporal coupled-mode theory with both an asymmetric gain distribution and local frequency detuning. We present experimental confirmations of the predicted mode evolution, mode hopping, and PT symmetry breaking with quantitative agreement with the theory.
Patrick Rauter - One of the best experts on this subject based on the ideXlab platform.
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multi wavelength quantum cascade Laser Arrays
Laser & Photonics Reviews, 2015Co-Authors: Patrick Rauter, Federico CapassoAbstract:The progress on multi-wavelength quantum cascade Laser Arrays in the mid-infrared is reviewed, which are a powerful, robust and versatile source for next-generation spectroscopy and stand-off detection systems. Various approaches for the array elements are discussed, from conventional distributed-feedback Lasers over master-oscillator power-amplifier devices to tapered oscillators, and the performances of the different array types are compared. The challenges associated with reliably achieving single-mode operation at deterministic wavelengths for each Laser element in combination with a uniform distribution of high output power across the array are discussed. An overview of the range of applications benefiting from the quantum cascade Laser approach is given. The distinct and crucial advantages of Arrays over external cavity quantum cascade Lasers as tunable single-mode sources in the mid-infrared are discussed. Spectroscopy and hyperspectral imaging demonstrations by quantum cascade Laser Arrays are reviewed.
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Multi‐wavelength quantum cascade Laser Arrays
Laser & Photonics Reviews, 2015Co-Authors: Patrick Rauter, Federico CapassoAbstract:The progress on multi-wavelength quantum cascade Laser Arrays in the mid-infrared is reviewed, which are a powerful, robust and versatile source for next-generation spectroscopy and stand-off detection systems. Various approaches for the array elements are discussed, from conventional distributed-feedback Lasers over master-oscillator power-amplifier devices to tapered oscillators, and the performances of the different array types are compared. The challenges associated with reliably achieving single-mode operation at deterministic wavelengths for each Laser element in combination with a uniform distribution of high output power across the array are discussed. An overview of the range of applications benefiting from the quantum cascade Laser approach is given. The distinct and crucial advantages of Arrays over external cavity quantum cascade Lasers as tunable single-mode sources in the mid-infrared are discussed. Spectroscopy and hyperspectral imaging demonstrations by quantum cascade Laser Arrays are reviewed.
Federico Capasso - One of the best experts on this subject based on the ideXlab platform.
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multi wavelength quantum cascade Laser Arrays
Laser & Photonics Reviews, 2015Co-Authors: Patrick Rauter, Federico CapassoAbstract:The progress on multi-wavelength quantum cascade Laser Arrays in the mid-infrared is reviewed, which are a powerful, robust and versatile source for next-generation spectroscopy and stand-off detection systems. Various approaches for the array elements are discussed, from conventional distributed-feedback Lasers over master-oscillator power-amplifier devices to tapered oscillators, and the performances of the different array types are compared. The challenges associated with reliably achieving single-mode operation at deterministic wavelengths for each Laser element in combination with a uniform distribution of high output power across the array are discussed. An overview of the range of applications benefiting from the quantum cascade Laser approach is given. The distinct and crucial advantages of Arrays over external cavity quantum cascade Lasers as tunable single-mode sources in the mid-infrared are discussed. Spectroscopy and hyperspectral imaging demonstrations by quantum cascade Laser Arrays are reviewed.
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Multi‐wavelength quantum cascade Laser Arrays
Laser & Photonics Reviews, 2015Co-Authors: Patrick Rauter, Federico CapassoAbstract:The progress on multi-wavelength quantum cascade Laser Arrays in the mid-infrared is reviewed, which are a powerful, robust and versatile source for next-generation spectroscopy and stand-off detection systems. Various approaches for the array elements are discussed, from conventional distributed-feedback Lasers over master-oscillator power-amplifier devices to tapered oscillators, and the performances of the different array types are compared. The challenges associated with reliably achieving single-mode operation at deterministic wavelengths for each Laser element in combination with a uniform distribution of high output power across the array are discussed. An overview of the range of applications benefiting from the quantum cascade Laser approach is given. The distinct and crucial advantages of Arrays over external cavity quantum cascade Lasers as tunable single-mode sources in the mid-infrared are discussed. Spectroscopy and hyperspectral imaging demonstrations by quantum cascade Laser Arrays are reviewed.
