Pulse shaping with birefringent crystals: a tool for quantum metrology

A method for time differentiation based on a Babinet-Soleil-Bravais compensator is introduced. The complex transfer function of the device is measured using polarization spectral interferometry. Time differentiation of both the pulse field and pulse envelope are demonstrated over a spectral width of about 100 THz with a measured overlap with the objective mode greater than 99.8%. This pulse shaping technique is shown to be perfectly suited to time metrology at the quantum limit

Imagerie tridimensionnelle multiphotonique des tissus biologiques à l'aide d'impulsions façonnées

This thesis presents the application of ultrashort pulses in the context of multiphoton microscopy and quantum optics. We will first introduce some pulse shaping techniques and we will detail in particular the operation and the characterization of our pulse shaping apparatus. We will study an optically addressed diffractive 2D phase mask, allowing both spectral and phase shaping. Then, we will see how pulse shaping can be an effective tool providing tunable selective fluorophore excitation in two-photon microscopy. Thus, we will present an experiment of coherent control of the 2-photon absorption in a developing drosophila embryo. Afterwards, we will describe a prism-based pulse shaping scheme in conjunction with a time-multiplexing approach of the pulses that allowed the simultaneous acquisition of multiple fluorophores. Ultimately, we will present the application of ultrashort pulses to measure time and dispersion at the standard quantum limit. In particular we will detail theoretically and experimentally a new pulse shaping scheme based on birefringent materials in order to produce the temporal derivative of the electric field or the temporal derivative of its envelope.Cette thèse présente l'utilisation d'impulsions ultracourtes pour des expériences de microscopie non-linéaire et d'optique quantique. Dans un premier temps, nous exposerons plusieurs techniques de façonnage d'impulsions et nous détaillerons en particulier le fonctionnement et la caractérisation de notre dispositif de façonnage. Nous étudierons l'utilisation d'un masque de phase 2D diffractif adressé optiquement qui permet un façonnage à la fois en phase et en amplitude spectrale. Par la suite, nous verrons comment le façonnage d'impulsions ultra-courtes peut être un outil efficace pour sélectionner les fluorophores excités en microscopie à deux photons. Pour cela, nous présenterons une expérience de contrôle cohérent de l'absorption à deux photons dans un embryon de drosophile vivant avec notre système de façonnage programmable. Ensuite nous décrirons un schéma de façonnage simplifié à base de prismes, qui, conjointement avec une approche de multiplexage temporel des impulsions, permet d'imager simultanément plusieurs fluorophores. Enfin, nous discuterons l'utilisation d'impulsions ultracourtes pour des expériences de mesures de temps et de dispersion à la limite quantique. Nous détaillerons en particulier une étude théorique et expérimentale d'un système de façonnage original à base de matériaux biréfringents pour produire la dérivée temporelle d'un champ électrique ou bien la dérivée temporelle de son enveloppe

Dispersion-based pulse shaping for multiplexed two-photon fluorescence microscopy

International audienceWe demonstrate selective two-photon excited fluorescence microscopy with shaped pulses produced with a simple yet efficient scheme based on dispersive optical components. The pulse train from a broadband oscillator is split into two subtrains that are sent through different amounts of glass. Beam recombination results in pulse-shape switching at a rate of 150 MHz. Time-resolved photon counting detection then provides two simultaneous images resulting from selective two-photon excitation, as demonstrated in a live embryo. Although less versatile than programmable pulse-shaping devices, this novel arrangement significantly improves the performance of selective microscopy using broadband shaped pulses while simplifying the experimental setup. Cop. 2010 Optical Society of America

Multiplexed two-photon microscopy of dynamic biological samples with shaped broadband pulses.

International audienceCoherent control can be used to selectively enhance or cancel concurrent multiphoton processes, and has been suggested as a means to achieve nonlinear microscopy of multiple signals. Here we report multiplexed two-photon imaging in vivo with fast pixel rates and micrometer resolution. We control broadband laser pulses with a shaping scheme combining diffraction on an optically-addressed spatial light modulator and a scanning mirror allowing to switch between programmable shapes at kiloHertz rates. Using coherent control of the two-photon excited fluorescence, it was possible to perform selective microscopy of GFP and endogenous fluorescence in developing Drosophila embryos. This study establishes that broadband pulse shaping is a viable means for achieving multiplexed nonlinear imaging of biological tissues

Imagerie tridimensionnelle multiphotonique des tissus biologiques à l'aide d'impulsions façonnées

Cette thèse présente l'utilisation d'impulsions ultracourtes pour des expériences de microscopie non-linéaire et d'optique quantique. Dans un premier temps, nous exposerons plusieurs techniques de façonnage d'impulsions et nous détaillerons en particulier le fonctionnement et la caractérisation de notre dispositif de façonnage. Nous étudierons l'utilisation d'un masque de phase 2D diffractif adressé optiquement qui permet un façonnage à la fois en phase et en amplitude spectrale. Par la suite, nous verrons comment le façonnage d'impulsions ultra-courtes peut être un outil efficace pour sélectionner les fluorophores excités en microscopie à deux photons. Pour cela, nous présenterons une expérience de contrôle cohérent de l'absorption à deux photons dans un embryon de drosophile vivant avec notre système de façonnage programmable. Ensuite nous décrirons un schéma de façonnage simplifié à base de prismes, qui, conjointement avec une approche de multiplexage temporel des impulsions, permet d'imager simultanément plusieurs fluorophores. Enfin, nous discuterons l'utilisation d'impulsions ultracourtes pour des expériences de mesures de temps et de dispersion à la limite quantique. Nous détaillerons en particulier une étude théorique et expérimentale d'un système de façonnage original à base de matériaux biréfringents pour produire la dérivée temporelle d'un champ électrique ou bien la dérivée temporelle de son enveloppe.This thesis presents the application of ultrashort pulses in the context of multiphoton microscopy and quantum optics. We will first introduce some pulse shaping techniques and we will detail in particular the operation and the characterization of our pulse shaping apparatus. We will study an optically addressed diffractive 2D phase mask, allowing both spectral and phase shaping. Then, we will see how pulse shaping can be an effective tool providing tunable selective fluorophore excitation in two-photon microscopy. Thus, we will present an experiment of coherent control of the 2-photon absorption in a developing drosophila embryo. Afterwards, we will describe a prism-based pulse shaping scheme in conjunction with a time-multiplexing approach of the pulses that allowed the simultaneous acquisition of multiple fluorophores. Ultimately, we will present the application of ultrashort pulses to measure time and dispersion at the standard quantum limit. In particular we will detail theoretically and experimentally a new pulse shaping scheme based on birefringent materials in order to produce the temporal derivative of the electric field or the temporal derivative of its envelope.PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF

Pulse shaping with birefringent crystals: a tool for quantum metrology

A method for time differentiation based on a Babinet-Soleil-Bravais compensator is introduced. The complex transfer function of the device is measured using polarization spectral interferometry. Time differentiation of both the pulse field and pulse envelope are demonstrated over a spectral width of about 100 THz with a measured overlap with the objective mode greater than 99.8%. This pulse shaping technique is shown to be perfectly suited to time metrology at the quantum limit.This work was supported by Agence Nationale de la Recherche project QUALITIME (ANR- 09-BLAN-0119), European ERC starting grant program Frecquam

High aspect ratio nanochannel drilling in glass by femtosecond laser pulse of high cone angle, high quality Bessel-Gauss beam

International audienceBessel beams are invariant solutions to the Helmoltz equation that can also propagate, with finite pulse energy at high intensity, in a quasi-invariant regime in transparent dielectrics. Homogeneous energy is deposited along a line focus by infrared ultrashort pulses. If the cone angle is sufficiently high, the laser-deposited energy density is enough to open nanochannels in glasses or sapphire with a single laser pulse. This has found applications in the field of glass cutting via the technique of "stealth dicing". Here we address two important challenges in this field. First, high quality Bessel beams are essential for controlled energy deposition. Second, the maximal angle used up to here for channel drilling was 26° for 800 nm laser central wavelength. This enabled the formation of channels with diameters down to typically 300 nm in glass and sapphire. It is questionable if higher cone angles could also produce channels with potentially smaller diameters. Here, we generate high quality Bessel-Gauss beams with a setup based on reflective, off-axis axicons. The Bessel zone exceeds 100 µm for cone angles up to 35 degrees. This corresponds to central spot diameter down to 0.5 µm FWHM. We qualified these beams with a 100 fs laser source centered at 800 nm wavelength. We report nanochannel drilling down to typically 100 nm over at least 30 µm length in glass. Our approach opens novel perspectives for high quality Bessel beam generation but also for the highly confined laser-matter interaction for high precision processing of transparent dielectrics