Ultrashort-pulse laser with an intracavity phase shaping element

A novel ultrashort-pulse laser cavity configuration that incorporates an intracavity deformable mirror as a phase control element is reported. A user-defined spectral phase relation of 0.7 radians relative shift could be produced at around 1035 nm. Phase shaping as well as pulse duration optimization was achieved via a computer-controlled feedback loop

Monitoring ultrashort pulses by transverse frequency doubling of counterpropagating pulses in random media

The authors study experimentally the transverse second-harmonic generation of counterpropagating pulses by a quasi-phase-matching in a medium with a random ferroelectric domain structure. The authors show that this parametric process results in a direct realization of the cross correlation of two optical signals and, therefore, it can be employed for direct characterizations of ultrashort pulses including their temporal structure and pulse front tilt.The authors acknowledge the support of the Australian Research Council

On the alleged phonetic value /p/ of the frog hieroglyph in Ptolemaic

The present article deals with two passages (Esna n° 379, 9 and Edfu III, 190, 2) which feature the frog hieroglyph with a supposed phonetic value /p/. While an alternative reading /H/ is suggested for the first text, the other requires returning to Nefertari’s tomb for disclosure of the frog’s meaning

Ultrashort-pulse laser calligraphy

Control of structural modifications inside silica glass by changing the front tilt of an ultrashort pulse is demonstrated, achieving a calligraphic style of laser writing. The phenomena of anisotropic bubble formation at the boundary of an irradiated region and modification transition from microscopic bubbles formation to self-assembled form birefringence are observed, and the physical mechanisms are discussed. The results provide the comprehensive evidence that the light beam with centrosymmetric intensity distribution can produce noncentrosymmetric material modifications

Direct frequency-comb-driven Raman transitions in the terahertz range

We demonstrate the use of a femtosecond frequency comb to coherently drive stimulated Raman transitions between terahertz-spaced atomic energy levels. More specifically, we address the $3d~^2D_{3/2}$ and $3d~^2D_{5/2}$ fine structure levels of a single trapped $^{40}$Ca$^+$ ion and spectroscopically resolve the transition frequency to be $\nu_D = 1{,}819{,}599{,}021{,}534 \pm 8$ Hz. The achieved accuracy is nearly a factor of five better than the previous best Raman spectroscopy, and is currently limited by the stability of our atomic clock reference. Furthermore, the population dynamics of frequency-comb-driven Raman transitions can be fully predicted from the spectral properties of the frequency comb, and Rabi oscillations with a contrast of 99.3(6)\% and millisecond coherence time has been achieved. Importantly, the technique can be easily generalized to transitions in the sub-kHz to tens of THz range and should be applicable for driving, e.g., spin-resolved rovibrational transitions in molecules and hyperfine transitions in highly charged ions.Comment: 9 pages, 8 figure

Personality factors in the movie: Parfume the story of murderer

In this Research, The writer analyzes and watches the movie Parfume: The Story Of Murderer by Tom Tykwer. The background of this research appears based on the deviation of the main character in making a parfume. This also relates to the characters in this drama. Then this study has two problem statements about how deviations in parfume presents in the movie Parfume The Story Of Murderer through the character, personality factors and plot about the consequences of personality factors especially by the main characters in the Movie Parfume The Story Of Murderer. To support analyzing this study, the researcher uses several theories that support such psychoanalysis from Sigmund Freud in Id, ego, superego. It is for analyzing human personality and also for analyzing Abraham Maslow's theory of humanitarian theory. As a research’s conclusion that the main character, Grenouille has shown the experiences levels from the symbol of the desire to kill woman just to make perfect parfumes. Finally, the consequences of the deviations that Grenouille did were very worrying for residents especially woman who were very afraid of the events or behaviors which shown the main character in this film. Because of the behavior main character itself, Grenouille is hunted by all people because he has been proven to commit irregularities and cruelty for killing girls to be used as material for making parfume The writer uses descriptive and qualitative method to collect the data that relate to the research. The data are observing and analyzing how the Personality Factors In The Movie Parfume The Story Of Murderer, finding personality factors and character by the main character in the movie. After watching and analyzing the movie, the writer got the conclusion that the events happened in the movie. Many interesting things like a main character make special parfumes and the parfumes makes other worship to grenouille and follow what the main character wanted. Based on the psychoanalytic approach factor that influence of the main character the first is Personal factor, second Biological factor it consist by natural environment and the last is social heritage. The intellectualization of Grenouille appears when he was a kid, when his friend disturbs him, he is just quite and watches them and do nothing. The reaction formation of Grenouille appears when Grenouille finally decides to make another perfume rather then think about himself. He makes positive thinking by creating a fragrance perfume just to fulfill his obsession in perfume and not for himself. The regression appears on Grenouille, even he is the man with no hearts, dares to kill a lot of women, but sometimes he feels lonely, happy, and also scares

A simple method for the determination of the structure of ultrashort relativistic electron bunches

In this paper we propose a new method for measurements of the longitudinal profile of 100 femtosecond electron bunches for X-ray Free Electron Lasers (XFELs). The method is simply the combination of two well-known techniques, which where not previously combined to our knowledge. We use seed 10-ps 1047 nm quantum laser to produce exact optical replica of ultrafast electron bunches. The replica is generated in apparatus which consists of an input undulator (energy modulator), and the short output undulator (radiator) separated by a dispersion section. The radiation in the output undulator is excited by the electron bunch modulated at the optical wavelength and rapidly reaches 100 MW-level peak power. We then use the now-standard method of ultrashort laser pulse-shape measurement, a tandem combination of autocorrelator and spectrum (FROG -- frequency resolved optical gating). The FROG trace of the optical replica of electron bunch gives accurate and rapid electron bunch shape measurements in a way similar to a femtosecond oscilloscope. Real-time single-shot measurements of the electron bunch structure could provide significant information about physical mechanisms responsible for generation ultrashort electron bunches in bunch compressors. The big advantage of proposed technique is that it can be used to determine the slice energy spread and emittance in multishot measurements. It is possible to measure bunch structure completely, that is to measure peak current, energy spread and transverse emittance as a function of time. We illustrate with numerical examples the potential of the proposed method for electron beam diagnostics at the European X-ray FEL.Comment: 41 pages, 18 figure

The time resolved measurement of ultrashort THz-band electric fields without an ultrashort probe

The time-resolved detection of ultrashort pulsed THz-band electric field temporal profiles without an ultrashort laser probe is demonstrated. A non-linear interaction between a narrow-bandwidth optical probe and the THz pulse transposes the THz spectral intensity and phase information to the optical region, thereby generating an optical pulse whose temporal electric field envelope replicates the temporal profile of the real THz electric field. This optical envelope is characterised via an autocorrelation based FROG measurement, hence revealing the THz temporal profile. The combination of a narrow-bandwidth, long duration, optical probe and self-referenced FROG makes the technique inherently immune to timing jitter between the optical probe and THz pulse, and may find particular application where the THz field is not initially generated via ultrashort laser methods, such as the measurement of longitudinal electron bunch profiles in particle accelerators.Comment: 7 pages, 3 figures, submitted to AP