p. A birefringent medium, a non nonlinear medium, a dispersive optical system, a parametric device (DFG) are successively used to achieve the generation.
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
ippp. A birefringent medium, a non nonlinear medium, a dispersive optical system, a parametric device (DFG) are successively used to achieve the generation.
The present invention is notably directed to methods and systems for generating a CEP-stable optical pulse of optical carrier frequency fi from input optical pulses, the input optical pulses having an optical carrier frequency fp and pulse duration Tp. A birefringent medium, a non nonlinear medium, a dispersive optical system, a parametric device (DFG) are successively used to achieve the generation.
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (France)
Inventor
Forget, Nicolas
Di Pietro, Vittorio
Jullien, Aurélie
Abstract
The invention relates to an optically-addressed reflective spatial light modulator (RSLM) for modulating the phase and/or the polarisation of an optical reading beam. The RSLM comprises a nematic phase liquid crystal layer that is greater than or equal to 20 micrometres thick, with the liquid crystal layer being between a first anchoring element and a second anchoring element. The RSLM comprises a first layer, disposed against the second anchoring element, having light reflecting properties, and a second layer, disposed against the first layer, having light absorbing properties.
G02F 1/13 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
5.
Generator of short optical pulses having a very high temporal contrast
A system for generating short optical pulses having a very high temporal contrast at a wavelength λ, includes: a generator of optical pulses B1 outputting pulses at a wavelength substantially equal to λ; a generator of optical pulses P, B2 outputting pulses at a wavelength substantially equal to 2*λ3; a device R for recombining the pulses from the generators; a parametric amplifier A receiving the output of the recombination device R as an input; a filter F2 extracting, from the output of the parametric amplification device A, a band centered about a wavelength equal to 2*λ; a second harmonic generator NL receiving the output of the filter F2, at the input; a filter F3 centered about a wavelength equal to λ, extracting the second harmonic wavelengths of the pulses produced by the second harmonic generator NL.
G02F 1/37 - Non-linear optics for second-harmonic generation
6.
System for generating short optical pulses of a duration shorter than the period of the optical carrier using the principle of parametric amplification
a programmable device making it possible to temporally adjust the pulses corresponding to the bands, in order to allow for the generation of a pulse with a wavelength equal to λ/3 and of a duration less than the period of the optical cycle.
G02F 1/11 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves
H01S 3/00 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
H01S 3/10 - Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
7.
Device for the temporal shaping of the amplitude and phase of ultrashort light pulses
A device for the temporal shaping of the amplitude and phase of ultrashort pulses, includes: —a birefringent waveguide 1 of main axis Δ consisting of a nematic liquid crystal 2 located between a photoconductive material 3 and a substrate 4, —two transparent electrodes, one of which 5 is located between the nematic liquid crystal 2 and the substrate 4, and the other 6 such that the photoconductive material 3 is located between the other electrode 6 and the nematic liquid crystal 2, and —projection optics 7 for projecting a programmable optical mask 8 onto the photoconductive material 3.
G02F 1/035 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on ceramics or electro-optical crystals, e.g. exhibiting Pockels or Kerr effect in an optical waveguide structure
G02F 1/13 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
G02F 1/01 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour
G02F 1/135 - Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied
G02B 6/10 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
The invention relates to a system for generating short optical pulses having a very high temporal contrast at a wavelength λ, including: a generator of optical pulses B1 outputting pulses at a wavelength substantially equal to λ; a generator of optical pulses P, B2 outputting pulses at a wavelength substantially equal to 2*λ3; a device R for recombining the pulses from the generators; a parametric amplifier A receiving the output of said recombination device R as an input; a filter F2 extracting, from the output of the parametric amplification device A, a band centered about a wavelength equal to 2*λ; a second harmonic generator NL receiving the output of said filter F2 , at the input; a filter F3 centered about a wavelength equal to λ, extracting the second harmonic wavelengths of the pulses produced by the second harmonic generator NL.
The invention relates to a short optical pulse generator including: a generator (P,B1) of optical pulses having a wavelength equal to λ/2 and a spectral width smaller than λ/3; a generator (P, B2) of optical pulses having a duration shorter than 10 picoseconds at a wavelength of λ/3; a device (RI) recombining the pulses from the generators; a parametric amplification device (OPA1) receiving, as an input, the output from the recombining device; a filter (F2) extracting, from the output of the amplification device, a band centered on a wavelength λ; a second harmonic generator (SH) receiving the output of the filter (F2) and generating a band centered on a wavelength λ/2; and a programmable device (DCDP2) enabling a time-based adjustment of the pulses corresponding to said bands such as to make it possible to generate a pulse having a wavelength equal to λ/3 and a duration lower than the period of the optical cycle.
A method and a system for scanning a time delay between a first ultrafast optical pulse of duration shorter than 10 ps and a second ultrafast optical pulse of duration shorter than 10 ps, wherein the second ultrafast pulse is submitted to an acousto-optic Bragg diffraction by an acoustic pulse in the bulk of an acousto-optic material and the delay scanning is produced by time variation of the acoustic pulse in the material.
G01J 11/00 - Measuring the characteristics of individual optical pulses or of optical pulse trains
G02F 1/11 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves
G01J 5/10 - Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
G01N 21/3581 - Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using far infrared lightInvestigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using Terahertz radiation
G01N 21/63 - Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
11.
DEVICE FOR THE TEMPORAL SHAPING OF THE AMPLITUDE AND PHASE OF ULTRASHORT LIGHT PULSES
A device for the temporal shaping of the amplitude and phase of ultrashort pulses, comprising: - a birefringent waveguide 1 of main axis Δ consisting of a nematic liquid crystal 2 located between a photoconductive material 3 and a substrate 4, - two transparent electrodes, one of which 5 is located between said nematic liquid crystal 2 and said substrate 4, and the other 6 such that said photoconductive material 3 is located between said other electrode 6 and said nematic liquid crystal 2, and - projection optics 7 for projecting a programmable optical mask 8 onto said photoconductive material 3.
G02F 1/01 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour
G02F 1/135 - Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied
12.
METHOD AND DEVICE FOR RECONSTRUCTIVE MULTI-SPECTRAL IMAGING
Method and device for reconstructive multi-spectral imaging using a fixed or movable instrument, comprising: measuring the intensity of the light coming from a secondary optical source obtained by acousto-optic diffraction 2 of the light originating from a primary optical source 1; acquiring said measurements of the intensity of the light from said secondary optical source; calibrating, for a given acoustic frequency, two functions relating, for each point M on the primary source 1 and for each instant, an image point m in the focal plane 4 to said point M on the primary source 1, and relating, for each point m in the focal plane 4, and for each wavelength of said primary source 1, the acoustic frequency enabling said acousto-optic diffraction 2 to the point m in said focal plane 4, respectively; and obtaining the intensity of the image corresponding to the point M on the primary source 1 by measuring the signal detected by a pixel in the position m in the focal plane 4, at one instant and for a given acoustic frequency.
A method and a system for scanning a time delay between a fîrst ultrafast optical pulse of duration shorter than 10 ps and a second ultrafast optical pulse of duration shorter than 10 ps, wherein said second ultrafast puise is submitted to an acousto-optic Bragg diffraction by an acoustic pulse in the bulk of an acousto-optic material and the delay scanning is produced by time variation of said acoustic puise in said material.
G02F 1/11 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves
14.
Device for compensation of time dispersion applied to the generation of ultrashort light pulses
The invention relates to a device for compensating the temporary scattering applied to the generation of ultra-short light pulses, said device including two identical and parallel optical diffraction gratings RA, RB and two identical prisms PA, PB that are placed inside the above-mentioned optical diffraction gratings RA, RB, given that the above-mentioned optical diffraction gratings RA, RB are volume phase gratings that function, during transmission, on the principle of Bragg diffraction. The outer surfaces FeA, FeB of the above-mentioned prisms PA, PB are parallel to the above-mentioned optical diffraction gratings RA, RB, and the inner surfaces FiA, FiB of the above-mentioned prisms PA, PB are parallel therebetween.
G02B 6/293 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
H01S 3/00 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
15.
AOTF DEVICE FOR THE PROGRAMMABLE ACOUSTO‑OPTICAL FILTERING OF HIGH SPECTRAL RESOLUTION AND OF LARGE ANGULAR APERTURE IN THE INFRARED REGION
The subject of the invention is an AOTF device for the programmable acousto‑optical filtering of high spectral resolution and of large angular aperture in the infrared region, comprising a birefringent acousto‑optical crystal TR, a transducer T ensuring the generation of a transverse acoustic wave, allowing a diffraction of an ordinary incident optical wave 0o, of incidence θo, into an extraordinary optical wave Od, of angle θd, knowing that the abovementioned diffraction is equivalent to a reflection close to the normal to the wave plane of the abovementioned incident optical wave Oo, the abovementioned angle θd of the diffracted optical wave Od is equivalent to the abovementioned angle of incidence θo of the incident optical wave 0o, plus a value lying between 160 and 180 degrees.
G02F 1/11 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves
The invention relates to a device for compensating the temporary scattering applied to the generation of ultra-short light pulses, said device including two identical and parallel optical diffraction gratings RA, RB and two identical prisms PA, PB that are placed inside the above-mentioned optical diffraction gratings RA, RB, given that the above-mentioned optical diffraction gratings RA, RB are volume phase gratings that function, during transmission, on the principle of Bragg diffraction. The outer surfaces FeA, FeB of the above-mentioned prisms PA, PB are parallel to the above-mentioned optical diffraction gratings RA, RB, and the inner surfaces FiA, FiB of the above-mentioned prisms PA, PB are parallel therebetween.
G02B 6/293 - Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
The method and device for measuring the spectral phase or combined spectral and spatial phases of ultra short light pulses, consisting of a decomposition of the light pulse to be measured in two identical replicas called signal pulse and primary reference pulse, respectively, of different polarization or direction and the phase characteristics of which are essentially identical to the original pulse, a temporal filtering of the primary reference pulse by a nonlinear interaction generating a secondary reference pulse of average frequency essentially identical and of spectral width greater than the spectral width of the primary reference pulse, and a spectral interferometry measurement by recombination of this secondary reference pulse and the signal pulse with a given temporal offset.
The subject matter of the invention is a method of high-resolution acousto-optic programmable filtering in the infrared region of an incident optical wave. To that end it proposes the use of a birefringent acousto-optic crystal whereof the propagation speed of acoustic waves is slow, such as compounds of mercury, which acousto-optic crystal comprises, on one of its faces, a piezoelectric transducer designed to generate a transverse acoustic wave with wave vector whereof the energy propagates according to the same axis but in the opposite direction to the energy of the incident optical wave, knowing that the optical wave resulting from the acousto-optic interaction between the incident optical wave and the acoustic wave with wave vector is diffracted perpendicularly or almost perpendicularly to the direction of the incident optical wave.
09 - Scientific and electric apparatus and instruments
Goods & Services
Scientific, optical, photographic, weighing, measuring,
signalling, checking (inspection), life-saving (rescue) and
teaching apparatus and instruments; apparatus for recording,
transmission or reproduction of sound or images; data
processing equipment and computers; software (recorded
programs), cameras (photographic apparatus), video cameras;
precision measuring apparatus, lasers, not for medical
purposes; laser power meters; amplifiers; programmable
acousto-optic filters, spectrometers; shutters (photography)
and stands therefor; mirrors (optics); photometers;
voltmeters, probes for scientific purposes.
09 - Scientific and electric apparatus and instruments
Goods & Services
scientific apparatus for use in the field of ultra fast laser, namely acousto-optic programmable device namely temporal filter of amplitude and phase stage; computer software programs for driving the acousto-optic programmable device, namely temporal filter of amplitude and phase stage
