Results 1 - 10 of 4558
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[en] Complete text of publication follows. A dialed theoretical studies on performances of the ideal RTP crystal for the electro optical applications as Q-switching laser operation and for nonlinear optics application as second harmonics generation are accomplished in this paper. Single or pair RTP crystal of excellent quality with dimensions 5 x 5 x 7.5 mm3 have proposed as element model to combined Q-switching operation and frequency doublers for 1.06 μm wave length laser. In order to get and interpolate the optimum conditions to combined both of these operations by application this RTP model. The main am of this work was investigated the most influent parameters on the performance of the electro optical Q-switching laser operation such as, the voltage requirement, contrast and extinction ratios, the birefringence effective and withstand threshold on the other hand the influences of the ray walk off, thermal effective on the efficiency of the second harmonics generation as well are investigated. The results were satisfied for the goals of this paper.
[en] We theoretically analyse quasi-phase matched second harmonic generation in a quadratic slot waveguide. Our results show that in this system both fundamental frequency and second harmonic (SH) modes can be confined in a nano-sized low-index region with the mode overlap integral intensity two orders larger than that achieved in the form birefringence phase matching slot waveguide and the conventional quasi-phase matched waveguide. For the unity length of 1.0 mm, the SH in the novel waveguide can be one order larger than those which have been investigated
[en] At the University of Maryland, the authors are exploring the suitability of gyroklystrons for linear collider applications. In this paper they discuss the design of a two-cavity, coaxial gyroklystron that is designed to produce over 100 MW in 1 μs pulses at the second harmonic of the cyclotron frequency. They detail modifications that will be required of their test facility, present the simulated performance of a 400 MW, 500 kV single-anode Magnetron Injection Gun, and describe the design of the coaxial microwave circuit
[en] This paper shows the feasibility of a harmonic-oscillation generator using a SNS microbridge biased by a dc voltage in the negative differential resistance range of its I-V characteristic curve. The frequency of the harmonic oscillations of this generator is equal to the resonant frequency of the tank RLC circuit. The principal features of this harmonic generator are discussed
[en] We derive the analytical expression of microcavity-enhanced factor for third harmonic generation in terms of detunings, linewidths, and the Purcell factors of the relevant microcavity modes. It is suitable for microcavities with any dimensions and arbitrary geometric shapes.
[en] High-harmonic generation with excitation pulses shorter than 25fs is studied theoretically using a 3D model. For very short excitation pulses, a new regime of harmonic generation by a open-quotes single-cycleclose quotes of the driver pulse can be reached. In this regime, the temporal coherence of the adjacent harmonic orders is dramatically improved compared with longer excitation pulses, even though the discrete harmonic structure in the emission disappears. X-ray pulses as short as 100attoseconds can be emitted, with increased conversion efficiency of laser-to-harmonic radiation. copyright 1997 The American Physical Society
[en] Despite the fact that high order harmonic generation (HHG) aims at serving as a table-top light source for imaging applications with extremely high spatial resolution, a general lack of accurate conversion efficiency measurements exists in the field. Here, we present such a measurement for a HHG setup with a semi-infinite gas cell. By combining measurements with a calibrated photodiode sensitive in the extreme ultra-violet (XUV) and spatially resolved spectral measurements of HHG spectra, we are able to determine conversion efficiencies of the HHG process as well as brilliance values for individual harmonics. The method is explained in detail and applicable to any target geometry. (authors)
[en] The two-color circularly polarized pulses scheme was proposed to generate isolated attosecond pulses in our previous work [Phys. Rev. A 87 (2013) 043406], while the polarization of the attosecond pulse was not investigated. We show a supplementary explanation of this scheme and present another scheme to generate linear isolated attosecond pulses by combining a circularly polarized pulse with an elliptically polarized pulse. High-order harmonic generation and quantum path control are investigated to compare these two schemes. Both schemes can obtain supercontinuum spectra plateau from about 200 eV to 550 eV, which belong to the water window region. It is found that the latter scheme can clearly eliminate the short quantum path and extend the harmonic plateau. A linear isolated attosecond pulse with a duration of sub-60 as can be generated by superposing a bandwidth of 70 eV. (paper)