Michel Piché

Followers

Following

Co-authors

Public Views

David Seamon

Kansas State University

KANNAN M

Central council for research in Siddha/Siddha Central Research Institute

David Vago

Vanderbilt University

Nelson Mauro Maldonato

Università degli Studi di Napoli "Federico II"

Michael Nichol

University of Southern California

Martin Hunter

Tufts University

Christopher Jeynes

University of Surrey

Anthony McCall

University of Virginia

Selwyn Vickers

University of Alabama at Birmingham

Henry Pitt

Temple University School of Medicine

Interests

Uploads

Papers by Michel Piché

$Research paper thumbnail of Phase-locking of 2-D laser arrays by diffractional coupling$

Phase-locking of 2-D laser arrays by diffractional coupling

Annual Meeting Optical Society of America

Phase-locking of semiconductor laser arrays can be achieved1 through evanescent wave coupling or ... more Phase-locking of semiconductor laser arrays can be achieved1 through evanescent wave coupling or Y junctions. More recently,2 a hollow bore ridge waveguide geometry has been used for phase-locking of CO2 lasers. We study the mode structure developed by 2-D laser arrays where phase-locking results from diffractional coupling. Three types of configuration are investigated: rectangular arrays of plane-parallel resonators with circular apertures; concentric arrays of resonators with circular apertures; and arrays of concentric curved surfaces of identical area.

Proposal for Generating Pairs of Synchronized Ultrafast Electron Bunches

The 22nd International Conference on Ultrafast Phenomena 2020, 2020

We show using test-particle simulations that the method of direct-field acceleration could be use... more

Digital holography under non paraxial conditions

The knowledge of the exact complex (amplitude and phase) wavefield scattered for different illumi... more The knowledge of the exact complex (amplitude and phase) wavefield scattered for different illuminating beams allows the computation of the 3D spatial distribution of a specimen. This work looks on how diffraction tomography can behave under high numerical aperture focusing conditions. Scalar theory is no longer valid in such system and nonparaxial vectorial field theory must be used. 'Numerical methods such as FDTD techniques can also be used to investigate the interaction of this field with the specimen.

Download

On the modelling of the optical properties of a metasurface composed of nanofins

OSA Advanced Photonics Congress (AP) 2020 (IPR, NP, NOMA, Networks, PVLED, PSC, SPPCom, SOF), 2020

The phase shift imparted by a dielectric nanofin metasurface can be modelled following a semi-ana... more

Download

using Z-scan techniques

Characterizing fluorescence and reflectance properties of Arctic macroalgae as future LiDAR targets

We consider the characteristics of macroalgal (kelp) targets of a LiDAR capable of assessing alga... more We consider the characteristics of macroalgal (kelp) targets of a LiDAR capable of assessing algal 3D morphology and quantifying algal biomass via fluorescence or differential absorption. Spectral absorption, fluorescence emission, fluorescence efficiency, and temporal fluorescence induction dynamics of Arctic algae can differ by class due to variation in photopigment complement. Surface reflectance characteristics of macroalgae can vary by morphology and structure. In this, work, we present an investigation of fluorescence via excitation-emission spectra of Arctic macroalgal targets. Simulations using these optical characteristics will later guide us in optimizing LiDAR configuration and performance under various operating conditions.

Self-mode-locking of solid-state lasers: the role of self-focusing and gain saturation

Coherent reshaping of picosecond infrared pulses in CO2 laser media

Conference on Lasers and Electro-Optics, 1985

Generation of optical Y-junction Bessel beams

Applied Optics, 2019

A method is proposed to split the central spot of zero-order Bessel beams into two parallel spots... more A method is proposed to split the central spot of zero-order Bessel beams into two parallel spots along the propagation axis of the beam. A magnetic-liquid deformable mirror is used to provide the required phase profile combining an axicon and a phase step. The obtained Y-junction Bessel beam has been characterized; the 80 µm central spot of the Bessel beam is split into two spots of the same size that have been propagated over a length exceeding 15 cm. The observations are consistent with the predictions of a numerical model. Potential applications of Y-junction Bessel beams are discussed.

Direct Laser Field Electron Acceleration in Relativistic Regime

High-Brightness Sources and Light-Driven Interactions, 2016

We discuss the experiments done with the 200 TW laser system at ALLS facility. A maximum intensit... more

A Review of Metallic Fractal Aggregates

Open Journal of Metal, 2011

Recent Studies in Electron Transport and Laser Interaction at INRS-ENERGIE

Laser Interaction and Related Plasma Phenomena, 1984

This article reviews some recent aspects of the work of the INRS group in the areas associated wi... more

Enhancement of modal feedback in large magnification unstable resonators using mirrors with multiple phase steps

Unstable resonators offer the most practical method of producing coherent beams of excellent opti... more Unstable resonators offer the most practical method of producing coherent beams of excellent optical quality out of laser media of large dimensions.1 However, according to geometric optics, the dominant modes of unstable resonators experience a net feedback per roundtrip given by 1 / M2, where M is the resonator magnification. As a result, conventional unstable resonators of large magnification are not suited for many laser media of large volume which have modest gain. In this paper, we describe how the use of multiple phase steps can alleviate the problem of low feedback while maintaining (or even improving) modal discrimination.

Optical characterization of linear and nonlinear materials using Bessel beams

SPIE Proceedings, 1998

We first recall that Bessel beams (or `diffraction-free beams&amp;amp;amp;#39;) can be produc... more We first recall that Bessel beams (or `diffraction-free beams&amp;amp;amp;#39;) can be produced by a Fourier optics setup where a mask with concentric transmission rings is placed at the focus of a lens. We then describe how the coherent superposition of Bessel beams with proper spatial frequencies leads to a self-imaging phenomenon. Such a behavior can be exploited to measure the

Hot-Electron Energy Deposition in CO2-Laser-Irradiated Targets Consistent with Magnetic-Field-Induced Surface Transport

Physical Review Letters, 1983

Hard-x-ray continuum spectra from high-Z tracers are used to obtain lateral and axial energy-depo... more Hard-x-ray continuum spectra from high-Z tracers are used to obtain lateral and axial energy-deposition profiles by hot electrons in CO2-laser-irradiated slab targets. The interpretation of the results emphasizes a local direction of incidence of the hot electrons on the target and an energy-deposition pattern which are consistent with self-generated magnetic fields.

Download

Generation and characterization of spatially and temporally localized few-cycle optical wave packets

Physical Review A, 2003

Direct experimental evidence of localized few-cycle wave packets with a characteristic spatiotemp... more Direct experimental evidence of localized few-cycle wave packets with a characteristic spatiotemporal X shape is reported. These wave packets are also referred to as X pulses. For their generation, a Ti:sapphire laser beam was transformed into single and array-shaped Bessel-like beams by using broadband refractive and reflective thin-film axicons. Extremely small conical angles allow a reduction of the spatially induced group velocity dispersion and therefore enhance the contrast. Complete first and second order spatiotemporal autocorrelation maps of sub-10-fs localized wave packets are measured and are compared with numerical simulations. High-power X pulses open further prospects for advanced nonlinear optical experiments like the formation of spatiotemporal solitons.

Download

Remote THz generation from two-color filamentation: long distance dependence

Optics Express, 2012

Remote terahertz (THz) generation from two-color filamentation is investigated as a function of t... more Remote terahertz (THz) generation from two-color filamentation is investigated as a function of the onset position of filaments. THz signals emitted by filaments produced at distances up to 55 m from the laser source were measured. However, from 9 m to 55 m, the THz signal decayed monotonically for increasing onset positions. With a simple calculation, the dominant factors associated to this decay were identified as group velocity mismatch of the two-color pulses and linear diffraction induced by focusing and propagating the second harmonic pulse.

Download

Photonic band gaps of transverse-electric modes in two-dimensionally periodic media

Journal of the Optical Society of America A, 1991

A rigorous analysis of the propagation of transverse-electric modes in two-dimensionally periodic... more A rigorous analysis of the propagation of transverse-electric modes in two-dimensionally periodic media is presented, based on an exact solution of the wave equation. The modulation functions studied lead to Mathieu and Hill equations. It is shown that the complete inhibition of the propagation of transverse-electric modes in a modulated plane is possible. Several modulation functions of the permittivity are studied in order to find the one for which the modulation depth necessary for the observation of a frequency band gap is minimized. In particular, thin grids and closely packed arrays of square rods are considered. The allowed angles of propagation of waves whose frequency is not contained within a forbidden band are also presented.

Single-mode pulses from a high-pressure CO/sub 2/ laser operated below emission threshold

IEEE Journal of Quantum Electronics, 1991

The authors describe a simple modification to the injection seeding method which has proved exper... more The authors describe a simple modification to the injection seeding method which has proved experimentally to yield reliable, single-mode emission from a 10-atm CO2 laser without the need for cavity length tuning. The technique consists of choosing the laser parameters such that the power oscillator is operated slightly below emission threshold, even though the gain can be above threshold for

Spontaneous emission in a nonhomogeneous medium: Definition of an effective polarizability

Physical Review A, 1992

The definition of an effective polarizability associated with a dipole transition is shown to res... more The definition of an effective polarizability associated with a dipole transition is shown to result from the use of a dyadic Green's function in solving the electron equation of motion obtained from a classical model of spontaneous emission that takes into account the presence of nonhomogeneities in the electric permittivity. This polarizability provides access to the line shape associated with the transition; it also provides a generalized procedure for studying the effects of changes in the electromagnetic environment on line shapes, frequency shifts, and transition rates.

Download

$Research paper thumbnail of Phase-locking of 2-D laser arrays by diffractional coupling$

Phase-locking of 2-D laser arrays by diffractional coupling

Annual Meeting Optical Society of America

Proposal for Generating Pairs of Synchronized Ultrafast Electron Bunches

The 22nd International Conference on Ultrafast Phenomena 2020, 2020

We show using test-particle simulations that the method of direct-field acceleration could be use... more

Digital holography under non paraxial conditions

Download

On the modelling of the optical properties of a metasurface composed of nanofins

OSA Advanced Photonics Congress (AP) 2020 (IPR, NP, NOMA, Networks, PVLED, PSC, SPPCom, SOF), 2020

The phase shift imparted by a dielectric nanofin metasurface can be modelled following a semi-ana... more

Download

using Z-scan techniques

Characterizing fluorescence and reflectance properties of Arctic macroalgae as future LiDAR targets

Self-mode-locking of solid-state lasers: the role of self-focusing and gain saturation

Coherent reshaping of picosecond infrared pulses in CO2 laser media

Conference on Lasers and Electro-Optics, 1985

Generation of optical Y-junction Bessel beams

Applied Optics, 2019

Direct Laser Field Electron Acceleration in Relativistic Regime

High-Brightness Sources and Light-Driven Interactions, 2016

We discuss the experiments done with the 200 TW laser system at ALLS facility. A maximum intensit... more

A Review of Metallic Fractal Aggregates

Open Journal of Metal, 2011

Recent Studies in Electron Transport and Laser Interaction at INRS-ENERGIE

Laser Interaction and Related Plasma Phenomena, 1984

This article reviews some recent aspects of the work of the INRS group in the areas associated wi... more

Enhancement of modal feedback in large magnification unstable resonators using mirrors with multiple phase steps

Optical characterization of linear and nonlinear materials using Bessel beams

SPIE Proceedings, 1998

Hot-Electron Energy Deposition in CO2-Laser-Irradiated Targets Consistent with Magnetic-Field-Induced Surface Transport

Physical Review Letters, 1983

Download

Generation and characterization of spatially and temporally localized few-cycle optical wave packets

Physical Review A, 2003

Download

Remote THz generation from two-color filamentation: long distance dependence

Optics Express, 2012

Download

Photonic band gaps of transverse-electric modes in two-dimensionally periodic media

Journal of the Optical Society of America A, 1991

Single-mode pulses from a high-pressure CO/sub 2/ laser operated below emission threshold

IEEE Journal of Quantum Electronics, 1991

Spontaneous emission in a nonhomogeneous medium: Definition of an effective polarizability

Physical Review A, 1992

Download

Michel Piché

Related Authors

Uploads

Papers by Michel Piché

Log In