We generated the second harmonics of pulses in the far-infrared region (30-55 microm), using the organic salt dimethylamino-4-N-methylstilbazolium tosylate (DAST). We demonstrate that DAST can be used to characterize ultrashort pulses in a spectral region where no other materials are available. To illustrate the need for such characterizations, we show the effects of propagation through air on ...

– Quantum mechanical analysis of the quantum confinement of ultrashort CMOS is numerically very expensive. In this paper we present a macroscopic model, which includes a new approach to match the vertical carrier profile and combines it with a classical model in lateral direction. The simulation results show a significant improvement concerning the accuracy of the carrier profile and the C/V ch...

In this Letter we discuss a novel method for generating ultrashort radiation pulses using a broadband two-stream instability in an intense relativistic electron beam. This method relies on an electron beam having two distinct two-energy bands. The use of this new high brightness electron beam scenario, in combination with ultrashort soft x-ray pulses from high harmonic generation in gas, allows...

By directly integrating the time-domain coupled-mode equations, we can explicitly obtain and examine the backward and forward propagating waves as a function of position and time within fiber grating structures. We apply this numerical procedure to calculate the temporal reflection and transmission response of fiber gratings subject to ultrashort pulse inputs. This allows us to study the dynami...

The interferometric measurement of an ultrashort optical pulse is demonstrated using three-photon ionization of Xe in a time-of-flight mass spectrometer (MS). This approach allowed measurement of the third-order fringe-resolved autocorrelation trace of an ultrashort optical pulse in the deep-ultraviolet (DUV) region. The pulse can be measured in-situ using the same MS that is employed in ultraf...

In order to explore new more powerful ultrashort pulse laser and tunable laser for diode-pumping, this paper reports the growth and spectral assessment of Yb(3+)-doped KBaGd(MoO(4))(3) crystal. An Yb(3+):KBaGd(MoO(4))(3) crystal with dimensions of 50×40×9 mm(3) was grown by the TSSG method from the K(2)Mo(2)O(7) flux. The investigated spectral properties indicated that Yb(3+):KBaGd(MoO(4))(3) c...

The storage-ring FEL at DELTA has been successfully operated with different filling patterns and temporal structures following the installation of new mirror chambers three years ago. The modulation depth of the opticalklystron spectrum was used to measure the electron energy spread. The measured FEL output power at high beam currents strongly exceeded the predictions of the low-gain model. Thi...

The properties of ultrashort gaussian pulse propagation in a dispersive, attenuative medium are reviewed with emphasis on the pulse velocity. Of particular interest is the group velocity whose physical interpretation loses meaning in causally dispersive materials as the temporal pulse width decreases into the ultrashort pulse regime. A generalized definition of the group velocity that applies t...

nanocomposite materials, including noble metal nanoparticles embedded in a dielectric host medium, are interesting because of their optical properties linked to surface plasmon resonance phenomena. for studding of nonlinear optical properties and/or energy transfer process, these materials may be excited by ultrashort pulse laser with a temporal width varying from some femtoseconds to some hund...

A femtosecond electron bunch is essential for the observation of ultrafast phenomena. In order to improve the time resolution of pulse radiolysis and ultrafast electron diffraction (UED), that involve the use of an ultrashort electron bunch and ultrashort light, a femtosecond photocathode RF gun was investigated experimentally. The bunch length due to space-charge and RF effects in the gun was ...