[en] The pulsed electron beam rf ion storage system is used to study neon ions electron transfer. The rate coefficients for electron transfer of the neon ions with the neon gas are measured. The results are better than those in other ion storage system

[en] It is always expected that the conversion efficiency is as high as possible for nonlinear interactions at any pump intensity. We present a method of controlling the conversion efficiency of sum-frequency generation in the periodic optical superlattices with different duty cycles, which is based on the controllable linear gratings induced by electro-optic effect here. The calculated results verify that this method is feasible and very efficient in attaining the complete transfer between the pump and sum-frequency waves at any given pump intensity. In addition, we demonstrate the electric-optic control is better than temperature control

[en] We report a theoretical study of the simultaneous high-efficiency, equal-level outputs of second and third harmonics in a quasiperiodic optical superlattice at any given fundamental intensity. The principle is that nonlinear coupling is effectively controlled by introducing proper quasiphase mismatches, by use of the tunability of linear refractive index gratings induced by applying a dc electric field based on the electro-optic effect. The theoretical results verify that this approach is feasible and very efficient. In addition, we also make a comparison with temperature tuning control, demonstrating that the performance of electro-optic control is much better than that of temperature tuning control

[en] A systematical investigation of the spectroscopic and ultrafast performance of Yb:CaLu_x Gd_1−x AlO₄ crystal (Yb:CLGA) was reported first in this work. A SESAM-based mode-locking laser was achieved by self-starting, generating reliable pulses as short as 69.6 fs. At a central wavelength of 1054 nm, a maximum average output power of 232 mW was obtained with the highest peak power of 63.7 kW. The same crystal was employed in wavelength tunable operation, and 65.7 nm of tuning range between 1023.1 nm and 1088.8 nm was obtained with a resolution of sub-0.1 nm. (letter)

[en] In order to study the thermal-hydraulic behavior of the cable-in-conduit-conductor (CICC), a numerical model has been developed. In the model, the high heat transfer approximation between superconducting strands and supercritical helium is adopted. The strong coupling of heat transfer at the front of normal zone generates a contact discontinuity in temperature and density. In order to obtain the converged numerical solutions, a moving mesh method is used to capture the contact discontinuity in the short front region of the normal. The coupled equation is solved using the finite element method with the artificial viscosity term. Details of the numerical implementation are discussed. Comparing the results with GANDALF and QSAIT, the validation of the code is performed. The quench study of CICC for the KSTAR TF coils is also performed. (author)

[en] Passively continuous-wave mode-locking (CWML) characteristics from a class of mixed Nd:Gd_xY_1_−_xVO_4 laser crystals at 1.34 μm have been investigated with a semiconductor saturable absorber mirror (SESAM) for the first time. In contrast to the single Nd:YVO_4 and Nd:GdVO_4 crystals, the mixed vanadate crystals can produce broader emission spectra, shorter pulse width, and higher peak power. Under the same conditions, the mode-locking performances from series mixed vanadate crystals as well as the emitting spectral properties were experimentally investigated. At an incident diode pump power of 7.1 W, a minimum pulse width was as short as 6.3 ps from the mixed vanadate crystal with x  =  0.63, while the highest peak power was 4.5 kW from the mixed crystal with x  =  0.83. (paper)

[en] We present a high power 340 W Nd:YVO₄ Innoslab laser end-pumped by 880 nm laser-diode stacks. A maximum output power of 340 W was obtained at the absorbed power of 710 W with optical conversion efficiency up to 47.9 %. At the output power of 300 W, the M² factors in the unstable direction and the stable direction were 2.1 and 3.4, respectively. (letter)

[en] A wavelength tuning experiment of a continuous-wave Ho,Pr:LiLuF₄ bulk laser operating at 2900 nm has been demonstrated for the first time. Two wavelength-tunable bands in the ranges of 2830–2902 nm and 2945–2956 nm were obtained. In addition, by using a semiconductor saturable absorber mirror, a high-peak-power passively Q-switched operation was realized. The shortest pulse width was 395 ns with a repetition rate of 7.29 kHz, corresponding to a peak power of 51.1 W. The results indicate the potential of Ho,Pr:LLF crystals for continuous-wave-tunable and passively Q-switched lasers operating at ∼3.0 µm. (letter)

[en] Continuous-wave and passively Q-switched (PQS) laser characteristics at 1.34 μm of a novel a-cut three matrix mixed laser crystal Nd:Lu_0.33Y_0.36Gd_0.3VO₄ with V³⁺:YAG as the saturable absorber were demonstrated. The maximum output power of 1.21 W was obtained at the pump power of 6.34 W, corresponding to an optical conversion efficiency of 19.1% and a slope efficiency of 23.5%. For the PQS operation at 1.34 μm, the minimum pulse width attained was 72.7-ns, with the pulse repetition rate of 103 kHz, with the single pulse energy and peak power estimated to be 5.18 μJ and 71.3 W, respectively. (paper)

[en] Dual-wavelength continuous-wave and Q-switched lasers are demonstrated in a Tm,Ho:GdYTaO₄ crystal under 790 nm laser diode end pumping for the first time to the best of our knowledge. The laser operates with a dual wavelength at 1949.677 nm and 2070 nm for continuous-wave with a spacing of about 120 nm. The maximum output power is 0.332 W with a pump power of 3 W. By using graphene as the saturable absorber, a passively Q-switched operation is performed with a dual-wavelength at 1950.323 nm and 2068.064 nm with a wavelength interval of about 118 nm. The maximum average output power of the Q-switched laser goes up to 200 mW with a minimum pulse duration of 1.2 µs and a maximum repetition rate of 34.72 kHz. (letter)