Diagnostics for Single Ultrashort Laser Pulses Using Transient-grating Frequency Resolved Optical Gating (FROG) PDF Download

Author: Anders Sjögren
Publisher:
ISBN:
Category :
Languages : en
Pages : 67

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Author: Rick Trebino
Publisher: Springer Science & Business Media
ISBN: 146151181X
Category : Science
Languages : en
Pages : 428

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Book Description
The Frequency-Resolved Optical-Gating (FROG) technique has revolutionized our ability to measure and understand ultrashort laser pulses. This book contains everything you need to know to measure even the shortest, weakest, or most complex ultrashort laser pulses. Whether you're an undergrad or an advanced researcher, you'll find easy-to-understand descriptions of all the key ideas behind all the FROG techniques, all the practical details of pulse measurement, and many new directions of research. This book is not like any other scientific book. It is a lively discussion of the basic concepts. It is an advanced treatment of research-level issues.

Author: Lina Xu
Publisher:
ISBN:
Category : Laser pulses, Ultrashort Measurement
Languages : en
Pages :

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In this thesis, we compare the performance of three versions of FROG to measure complex ultrashort laser pulses: second-harmonic-generation (SHG) FROG, polarization-gate (PG) FROG, and cross-correlation FROG (XFROG). We found that the XFROG algorithm achieves 100% convergence, while PG FROG and SHG FROG GP algorithm achieve 100% convergence after doing the noise deduction and increasing the sampling range.

Author: Dongjoo Lee
Publisher:
ISBN:
Category : Laser pulses, Ultrashort
Languages : en
Pages :

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Book Description
In the past several decades the technology for the creation and use of ultrashort pulses has progressed tremendously. Now, it is possible to generate laser pulses as short as a few femtoseconds in duration, and such pulses have been used for a wide range of applications. In addition, the means of measuring these pulses has progressed so rapidly. However, despite recent great advances in ultrashort-pulse measurement techniques, much remains to be done. In particular, pulse-measurement devices have relatively small wavelength-tuning ranges, and the phase-match is problematic for the pulses with a wide bandwidth such as supercontinuum. In this thesis, I will demonstrate a new pulse measurement technique which can phase-match ultra-broad bandwidth of super-continuum using transient grating frequency-resolved-optical-gating (TG FROG). Also, I will demonstrate a simplified device which can measure the UV ultra-short pulse using transient grating process, one of the third-order nonlinearity and can cover from UV to IR with the same arrangement.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Recently several techniques have become available to measure the time- (or frequency- ) dependent intensity and phase of ultrashort laser pulses. One of these, Frequency-Resolved Optical Gating (FROG), is rigorous and has achieved single-laser-shot operation. FROG combines the concepts of time-frequency analysis in the form of spectrogram generation (in order to create a two-dimensional problem), and uses a phase-retrieval-based algorithm to invert the experimental data to yield the intensity and phase of the laboratory laser pulse. In FROG it is easy to generate a spectrogram of the unknown signal, and inversion of the spectrogram to recover the signal is the main goal. Because the temporal width of a femtosecond laser pulse is much shorter than anything achievable by electronics, FROG uses the pulse to measure itself. In FROG, the laser pulse is split into two replicas of itself by a partially reflecting beamsplitter, and the two replicas interact with each other in a medium with an instantaneous nonlinear-optical response. This interaction generates a signal field that is then frequency-resolved using a spectrometer. The spectrum of the signal field is measured for all relevant values of the temporal delay between the two pulses. Here, the authors employ FROG and FROG related techniques to measure the time-dependent intensity and phase of an ultrashort laser pulse.

Author: Tsz Chun Wong
Publisher:
ISBN:
Category : Laser pulses, Ultrashort Measurement
Languages : en
Pages :

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Frequency-resolved optical gating (FROG) is the standard for measuring femtosecond laser pulses. It measures relatively simple pulses on a single-shot and complex pulses using multi-shot scanning and averaging. However, experience from intensity autocorrelation suggests that multi-shot measurements may suffer from a coherent artifact caused by instability in the laser source. In this thesis, the coherent artifacts present in modern pulse measurement techniques are examined and single-shot techniques for measuring complex pulse(s) are proposed and demonstrated. The study of the coherent artifact in this work shows that modern pulse measurement techniques also suffer from coherent artifacts and therefore single-shot measurements should be performed when possible. Here, two single-shot experimental setups are developed for different scenarios. First, an extension of FROG is developed to measure two unknown pulses simultaneously on a single-shot. This setup can measure pulses that have very different center wavelengths, spectral bandwidths, and complexities. Second, pulse-front tilt is incorporated to extend the temporal range of single-shot FROG to tens of picoseconds which traditionally can only be attained by multi-shot scanning. Finally, the pulse-front tilt setup is modified to perform a single-shot measurement of supercontinuum, one of the most difficult pulses to measure due to its long temporal range, broad spectral bandwidth, and low pulse energy.

Author:
Publisher:
ISBN:
Category : Laser pulses, Ultrashort
Languages : en
Pages : 312

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Author: Kaoru Yamanouchi
Publisher: Springer
ISBN: 3319236571
Category : Science
Languages : en
Pages : 216

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Book Description
This volume covers a broad range of topics focusing on atoms, molecules, and clusters interacting in intense laser field, laser induced filamentation, and laser plasma interaction and application. The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed articles authored by researchers at the forefront of each their own subfields of UILS. Every chapter opens with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Gabriel Andrew Marcus
Publisher:
ISBN:
Category :
Languages : en
Pages : 159

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This work studies the production and measurement of longitudinally coherent, ultrashort pulses of light from a self-amplified spontaneous emission free-electron laser (SASE FEL) by using an energy-chirped electron beam in conjunction with a tapered undulator. This scheme effectively preserves the FEL gain only where an appropriate undulator taper compensates for the detuning experienced by an amplifying radiation spike as it slips forward in the electron beam rest frame. The simultaneous time and frequency-domain measurement of ultrashort pulses of light generated in this manner were made with an advanced transient-grating frequency-resolved optical gating (TG FROG) diagnostic, which has the potential to push ultrashort light pulse measurement at FEL facilities to shorter wavelength regimes. The theoretical framework presented in this dissertation has two components. The FEL theory presented here includes an analysis of the coupled wave and Vlasov equations, which are linearized in the one-dimensional case, and are solved in the frequency domain by the Laplace transform technique. The exponential gain regime for SASE FEL light is explored in detail to clearly identify concepts that are relevant to the energy-chirp and undulator tapering experiment. Some of these concepts are illustrated with fully three-dimensional, time-dependent numerical particle simulations using the FEL code GENESIS for the supportive case of ultrashort, low-charge electron beams. In addition, nonlinear optics, the foundation upon which all FROG diagnostics are built, is briefly explored using two complementary perspectives as they apply to the TG FROG geometry. The experimental section describes in detail the first direct time-domain measurements of a single coherent radiation spike from a SASE FEL amplifier employing the energy-chirped electron beam and tapered undulator technique at the SPARC FEL test facility in Frascati, Italy. Electron beams were accelerated and compressed using the velocity bunching technique, which leaves a residual energy-chirp in the longitudinal phase space. The energy-chirp was compensated by appropriately tapering individual undulator sections. This process was optimized at a resonant wavelength of & lambda; = 530 nm. The ultrashort light pulses that were generated had a temporal full-width at half-maximum of 98 fs and a time-bandwidth product of TBP & sim; 1.2, indicating that the Fourier limit was nearly achieved. This experiment provides further insight into methods that can be used to shape the SASE FEL longitudinal profile and enhance coherence properties. In addition, the measurements were taken with an advanced, and relatively simple, TG FROG diagnostic that can potentially be used to measure ultrashort UV pulses at FEL facilities.