Simultaneous dual-wavelength CW operation using F3/2–I13/2 transitions in Nd:YVO4 crystal

We experimentally demonstrate a dual-wavelength continuous wave (CW) Nd:YVO₄ laser simultaneously operating at 1342 and 1386 nm. A total output power of 439 mW is achieved when the laser is diode-end-pumped at an incident pump power of 2.4 W, indicating a slope efficiency of 35.6%. To the best of our knowledge, it is the first time that simultaneous dual-wavelength CW operation at 1342 and 1386 nm is reported.     

A tunable optical parametric generator by using a quasi-phase-matched crystal with different wedge angles

We report a tunable quasi-phase-matched optical parametric generator (OPG) with different wedge angles, pumped by a commercially available Q-switched diode-pumped Nd:YVO4 laser with a repetition of 50 kHz.The nonlinear crystal is a periodically poled MgO-doped LiNbO3 (PPMgOLN) with a period of 30 μm.A congruent bulk LiNbO3 (LN) with three different wedge angles of 0°, 4°, and 9° is placed in front of PPMgOLN. Rapid tuning has been achieved by simply moving the LN crystal along its lateral direction and over 60-mW average signal output power was obtained in the whole wavelength tuning range of 1539-1570 nm.     

Simultaneous Degradation of Aqueous Trichloroacetic Acid by the Combined Action of Anodic Contact Glow Discharge Electrolysis and Normal Electrolytic Processes at the Cathode

To enhance the removal of trichloroacetic acid (TCA) by anodic contact glow discharge electrolysis (CGDE), the combined degradation of TCA by the action of anodic CGDE, denoted anodic degradation, and normal electrolytic processes at the cathode, denoted cathodic degradation, was investigated. Here, this overall process is termed simultaneous degradation. Compared to anodic degradation, in simultaneous degradation, the reduction rates for TCA and total organic carbon (TOC) increased from 65.32% and 62.03% to 91.82% and 73.03%, respectively. Meanwhile, the dechlorination rate rose from 64.6 to 80.12%. For simultaneous degradation, the disappearance of TCA, the reduction in the TOC, and the dechlorination of TCA, followed first-order kinetics. The reaction intermediates were detected and, based on the intermediates and the observed kinetics, the effects of the simultaneous degradation of TCA, TOC, and dechlorination of TCA are discussed. The cathode materials, length of the anode dipped into the electrolyte, and Pd loading on the Ni cathode all affected the simultaneous degradation of TCA significantly. The effect of the addition of Fe²⁺ was also investigated. The additive and synergistic effects of the combination of anodic and cathodic degradations on simultaneous degradation are discussed. Based on these results, an analysis of the degradation of TCA suggests that ·OH and ·H/e ^?_aq generated by the action of anodic CGDE, as well as the ·H_ads generated on the Pd-loaded Ni cathode surface, are the key species responsible for the dechlorination of TCA. Furthermore, possible mechanistic routes for the simultaneous degradation of TCA are proposed.

     

准相位匹配周期极化高掺镁铌酸锂532 nm倍频准连续输出研究

对周期性极化高掺镁铌酸锂倍频过程进行了准相位匹配倍频理论研究。在室温下通过外加电场极化法,用较低的极化开关电场～5．5kV／mm,在厚为1mm、长为10mm、宽为10mm的掺镁铌酸锂基片上成功地制备了周期为5．8～7．3pm(间隔0．3pm)的一阶准相位匹配倍频周期性极化光学微结构。将温度控制在70℃左右,以波长为1．060μm的Nd：YAG激光为基频光源,对所研制的光学微结构样品进行倍频通光实验验证。当入射基频光为920mW时,可以获得约15mW的532nm准连续倍频蓝光输出．其归一化转换效率高达1．77％／W。     

High-average-power,high-repetition-rate dual signal optical parametric oscillator based on PPMgLN

<正>A high-average-power,high-repetition-rate dual signal optical parametric oscillator based on periodically poled MgO-doped lithium niobate(PPMgLN) with a phase-reversed grating is reported.The pump laser is an acousto-optically Q-switched Nd:YVO_4 laser with a maximum average power of 7.6 W.When the repetition rate is 50 kHz and the pulse width of the pump source is 23 ns,the maximum average dual signal output power is about 1.9 W,leading to a conversion efficiency of 25%.Over a 30-min interval,the instability of the signal power measured is less than 0.5%.