High efficiency ultrafast waterwindow harmonic generation. Finally we will look at the future prospects for hhg spectroscopy of. Pdf development of high harmonic generation spectroscopy. Figure 2 illustrates the spectrum obtained from ar at 14 bar backing pressure for a laser intensity of 1014 w cm. Shaw3, avner fleischer1,4, henry kapteyn2, margaret murnane2 and oren cohen1.
The possibility to extract useful dynamical and structural information from the measurement of the hhg emission, a technique termed high harmonic generation spectroscopy hhgs, will be the special focus of our discussions. Related content introduction to macroscopic power scaling principles for high order harmonic generation c m heyl, c l arnold, a. In our experiments a portion of the residual 800 nm. In this work, we have used timedependent configuration interaction with a gaussian basis set to compute the hhg spectrum of the hydrogen atom. Ultrafast gas phase spectroscopy using high harmonic. These approaches may also work for lowrepetitionrate xfels 17 or high power high harmonic generation light sources 31 as long as two color xray pulses are available. The high harmonic spectrum has characteristic features figure 1. Highorder harmonic generation in laser plasma plumes. The harmonic spectrum was then detected by means of a soft xray spectrometer and a microchannel plate coupled to a phosphor screen and a charge coupled device camera. Full characterization of a molecular cooper minimum using.
However, current techniques offer phase measurements only along specific directions, thus. Pdf generation of bright circularlypolarized extreme. An apparatus for quantitative highharmonic generation. Timeresolved phasesensitive second harmonic generation. High harmonic generation hhg provides a flexible framework for the. Pdf high harmonic frequency combs for high resolution. That is, its frequency range extends well beyond the ionization potential ip of the source atom. Development and application of extreme ultraviolet light. We perform high harmonic generation spectroscopy of aligned nitrogen molecules to characterize the attosecond dynamics of multielectron rearrangement during strongfield ionization. Opening a new route to multiport coherent xuv sources via.
Attosecond science based on high harmonic generation from gases. This shows that the hhg spectrum can cover the water window by using short wave infrared swir lasers. Marangos,1 and misha ivanov1,2 1blackett laboratory, imperial college london, london sw7 2az, united kingdom 2max born institute, 12489 berlin adlershof, germany. Measurement of the berry curvature of solids using high.
This is known as high harmonic spectroscopy hhs 7,8. Multidimensional high harmonic spectroscopy of polyatomic. Introduction a central goal of attosecond spectroscopy is the observation of electronic motion in the molecular frame 1. Highharmonic spectroscopy is the application of highharmonic generation to atoms, molecules and the condensed phase to study static and dynamic properties of these systems. Introduction atoms and molecules exposed to an intense infrared ir laser. High harmonic generation an overview sciencedirect topics. Phasematched high order harmonic generation and applications.
We found in our experiments that a wavelength of 0 nm offers a good compromise between a significant cutoff extension and adequate hhg generation efficiency. Efficient highharmonic generation from a stable and. We study theoretically and experimentally high order harmonic generation hhg using two noncollinear driving fields focused in gases. Timefrequency analysis of high harmonic generation using a probe xuv pulse.
It produces a coherent, wide spectrum of several harmonic lines, which makes hhg a widely used method to generate ultrashort probe pulses for timeresolved. The roles of photocarrier doping and driving wavelength in. The electric field from a femtosecond nir laser pulse tunnel ionizes an electron away from the nucleus of an atom. Generation of bright circularlypolarized extreme ultraviolet high harmonics for magnetic circular dichroism spectroscopy ofer kfir1, patrik grychtol2, emrah turgut2, ronny knut2,3, dmitriy zusin2, dimitar popmintchev2, tenio popmintchev2, hans nembach3, justin m. Ultrasensitive chiral spectroscopy by dynamical symmetry. Introduction ever since their discovery, chiral molecular systems have puzzled and inspired researchers. The roles of photocarrier doping and driving wavelength. Photoelectron spectroscopy using high order harmonic generation. For the extending hhg spectroscopy is that while the small mol generation of high order harmonic radiation, the midir ecules studied so far typically have ionization potentials ip in driving pulses were focused on a synchronized gas jet oper the range 1512 ev most molecules have lower ip. May 05, 2020 a broadband xray light source, such as high order harmonic generation hhg 3, 4 and free electron laser 5, 6, is needed to create such superpositions, via ionization or the raman process. High harmonic spectroscopy of ultrafast manybody dynamics in. High harmonic generation hhg in the context of this project refers to the generation of. Highharmonic generation from spinpolarised defects in solids npj.
High order harmonic generation hhg produced by the interaction of an intense laser pulse and a gas medium can provide a table top scale coherent radiation source in the short wavelength range from the ultraviolet to the soft xray region. High harmonic generation spectroscopy directly probes the strong. Kapteyn the recent developments of high repetition rate and high average power ultrafast laser open the door for probing molecular structure and dynamics with intense laser. Extreme ultraviolet high harmonic generation and spectroscopy in solids. Timeresolved highharmonic spectroscopy of ultrafast photo. Highharmonic spectroscopy offers a number of attractive features that can be exploited to perform unusually accurate and exceptionally sensitive measurements. J, 350fs output pulses with diffractionlimited beam quality at a repetition rate of 16. High harmonic generation hhg electron motion in atoms and molecules. Xray spectroscopy and metrology with highharmonic sources.
Pdf extension of high harmonic spectroscopy in molecules. Atomiclike highharmonic generation from twodimensional. Highharmonic spectroscopy ultrafast spectroscopy and. High harmonic spectroscopy of ultrafast manybody dynamics. The analysis of photochemical processes has been previously limited by the short time scale in which these processes occur. However, it can be difficult to compare theory and experiment, since the dynamics under investigation are often very sensitive to the laser intensity, which. Here, by using high harmonic generation spectroscopy, we reveal the underlying attosecond dynamics that dictates the tem poral evolution of carriers in multiband solidstate sy stems. Harmonics of very high orders are generated from atoms and molecules exposed to intense usually nearinfrared laser fields. Half an optical cycle later when the electric field of the laser reverses. Kapteyn high harmonic generation hhg is an extreme nonlinear optical process, in which visible. Reconstruction of correlationdriven electronhole dynamics. High order harmonic spectroscopy of molecular structure and dynamics thesis directed by prof.
High harmonic generation from gases produces attosecond bursts and enables high harmonic spectroscopy to explore electron dynamics in atoms and molecules. Energy shifts and rydberg structures, katarzyna krajewska, ilya i. We show that these two fields form a nonstationary blazed active grating in the generation medium. Additionally, solidstate media offers unprecedented possibilities to control high harmonic generation using modified. Femtosecond timeresolved photoelectron spectroscopy with a vacuumultraviolet photon source based on laser high order harmonic generation rev. Highorder harmonic spectroscopy of molecular structure and. Macroscopic properties of highorder harmonic generation from. During the past decade, pumpprobe attosecond spectroscopy, by means of synchronized fewcycle pump pulses with extremeultraviolet xuv. This high harmonic generation results in coherent light pulses of high brightness into the xray region of the spectrum. Highharmonic and terahertz wave spectroscopy hats for.
On account of the strong nonlinearity of the ionization process, hhs of molecules can sensitively and selectively probe the highest occupied molecular orbitals homos, which are of prime importance for understanding chemical reactions. Leveraging these results, we examine how such multidimensional analyses pave the way for the study of charge migration with high harmonic spectroscopy and illustrate the bene. Half an optical cycle later when the electric field of the laser reverses direction, the electron is accelerated back towards the nucleus, coherently emitting an xuv. Pdf highorder harmonic generation in an active grating. Ulrafast xuv and soft xray spectroscopy resolve structures during lithography and after production with subnm precision l. We present an apparatus for performing gas phase high harmonic generation spectroscopy of molecules primarily found in the liquid phase. Several techniques involving xray, such as raman scattering 7 and attosecond streaking 8, 9, have been applied to measure the ultrafast.
High order harmonic generation spectroscopy with an elliptically polarized laser field, m. Modern advancement in ultrafast lasing technology allows for the. Molecular high harmonic generation spectroscopy high harmonic generation can be described by the widely used threestep model. Jul 02, 2019 ultrasensitive chiral spectroscopy by dynamical symmetry breaking in high harmonic generation ofer neufeld, david ayuso, piero decleva, misha y. Ultrafast gas phase spectroscopy using high harmonic generation.
Historically, ultrafast extreme ultraviolet sources employing high order harmonic generation hhg have required compromises that make it challenging to achieve a high energy resolutionwhich is highly desirable for many trarpes studieswhile producing high photon energies and a high photon flux. In particular, the phase of harmonic emission was shown to carry profound insight into atomic and molecular structure and dynamics. High harmonic generation from surface states of solids arxiv. High harmonic generation hhg is widely used for upconversion of amplified near infrared ultrafast laser pulses to short wavelengths. Timeresolved photoelectron spectroscopy trpes has been used to study the ultrafast relaxation of electronically excited thymine, thymidine, and thymidine monophosphate on femtosecond time scales in liquid water. Feature article multidimensional molecular high harmonic spectroscopy. Timefrequency analysis of high harmonic generation using a. High harmonic generation hhg is a nonlinear process during which a target gas, plasma, solid or liquid sample is illuminated by an intense laser pulse. High harmonic spectroscopy hhs is an emerging technology that promises the capability of studying the fastest processes that exist today. All measurements are performed at room temperature 300k. As a rst proof of principle experiment hhg based arpes. Strongfield methods in solids enable new strategies for ultrafast nonlinear spectroscopy and provide alloptical insights into the electronic properties of condensed matter in reciprocal and real space. The generation of high harmonics in the spectra of strongly laserdriven atoms has inspired much experimental.
To get a correct description of the hhg optical spectrum, the. Cavityenhanced high harmonic generation for extreme. The advancements of the experimental techniques of highharmonic spectroscopy as well as their theoretical description culminate in chapter7. Attosecond science based on high harmonic generation from. Stagira,b a istituto di fotonica e nanotecnologie cnr, 203 milan, italy b dipartimento di fisica politecnico di milano, 203 milan, italy. Attosecond spectral singularities in solidstate high. Although attosecond science holds the promise of accessing the timescale of. High harmonic generation and ionization effects in cluster targets. High harmonic generation spectroscopy of hydrocarbons. Highorder harmonic spectroscopy of molecular structure. High harmonic spectroscopy utilizes the extremely nonlinear optical process of high order harmonic generation hhg to measure complex attosecondscale dynamics within the emitting atom or molecule subject to a strong laser field. Development of high harmonic generation spectroscopy of organic. High harmonic spectroscopy of multichannel dynamics in. Under such conditions, the sample will emit the high harmonics of the generation beam above the fifth harmonics.
We demonstrate that ramseycomb spectroscopy, based on two such pulses derived from a frequencycomb laser, enables us to observe phase effects in this process with a few mrad precision. Dimauroa a department of physics, the ohio state university, columbus, oh 43210, usa bdepartment of physics and astronomy. The system used commercial singlemode, polarization maintaining fiber technology. Extremely nonlinear spectroscopy based on high order harmonic generation has become a powerful investigation method for attosecond dynamics in gas and solid targets.
Hhs is based on the process of high harmonic generation hhg which arises from the non. Detecting electronic coherences by timedomain highharmonic. Enhancing and controlling singleatom highharmonic generation. Recently, high harmonic generation from solids has been reported, resulting in novel phenomena and unique control of the emission, absent in gasphase media. High order harmonic spectroscopy for molecular imaging of polyatomic molecules arxiv. Pdf high harmonic generation spectroscopy of hydrocarbons. Photoelectron spectroscopy using high order harmonic. The intensity and phase structure of this grating rule the farfield properties of the emission, such as the relative amplitude of the diffraction orders. The harmonic signal scales with the laser wavelength as.
Results reveal that photoexcited co3o4 decays to the ground state in 600 40 ps in liquid methanol compared to 1. High harmonic spectroscopy of electron localization in the. Transient absorption spectroscopy using high harmonic generation. Efficient terahertz harmonic generation with coherent. Highorder harmonic spectrum of monolayer hexagonal boron nitride h bn with a boron vacancy. Development of high harmonic generation spectroscopy of. Experimental set up of high harmonic generation based angle resolved photoemission spectroscopy hhg based arpes has been developed and characterized. Highprecision ramseycomb spectroscopy based on high. High order harmonic generation with j laser pulses at high repetition rates to cite this article. Probing collective multielectron dynamics in xenon with high.
Extreme ultraviolet high harmonic generation and spectroscopy in. Kinetic analysis suggests that surfacemediated relaxation of photoexcited co3o4 may be the result of hole transfer. Highorder harmonic generation with muj laser pulses at. Ivanov1,6,7, y 3 1maxborninstitut, max born strasse 2a, d12489 berlin, germany 4 2russian quantum center, skolkovo 143025, russia 5. High harmonic generation is the nonlinear response of atoms, ions, or even of a steep densitygradient plasma to interaction with an intense electromagnetic field 38. Charge carrier dynamics in co3o4 thin films are observed using high harmonic generation transient absorption spectroscopy at the co m2,3 edge. Similar to generating the supercontinuum highharmonic spectrum, the required bandwidth is. Third harmonics are detectable with a tabletop light source and can be as strong as 100 v cm by applying a fundamental field of 6. At such a repetition rate, the mode spacing of the frequency comb, which is expected to survive the high harmonic generation process, is large enough for high resolution spectroscopy. The last decade has witnessed fundamental progress in the observation. Transient absorption spectroscopy using high harmonic. Pdf high efficiency ultrafast waterwindow harmonic. High harmonic generation hhg is used to produce coherent xuv and soft xray radiation with attosecond resolution and is a sensitive tool for probing atomic and molecular structures. Harmonic generation for harmonic generation for n 5 \displaystyle n5 5hg or more is theoretically possible, but the interaction requires a very high number of photons to interact and has therefore a low probability to happen.
Starace pdf threshold effects in strongfield ionization. Twodimensional phase cartography for highharmonic spectroscopy. High harmonic spectroscopy provides a unique insight into the electronic structure of atoms and molecules 1,2,3,4,5. The experimental production of high harmonics is sketched in fig. Charge carrier dynamics of photoexcited co3o4 in methanol.
Introduction recent advances in laser science have shed new light on the realtime observation and manipulation of the atomicscale motion of electrons 1. The setup is intended for ultrafast time resolved measurement of bandstructure dynamics on the attosecond time scale. High harmonic generation hhg electron motion in atoms and molecules the electric field from a femtosecond nir laser pulse tunnel ionizes an electron away from the nucleus of an atom. Liquid molecular samples are heated in a temperature controlled bath and their vapour is used to back a continuous ow gas jet, with vapour pressures of over 1 bar possible.
251 160 354 456 1120 858 1320 854 1426 985 1152 1255 198 1295 1041 1484 1525 461 1066 231 782 110 108 420 396 446 926 656 437 1200 712 367 1428