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We report a compact all-solid-state mid-infrared optical parametric oscillator with wide tunability using periodically poled 5 mol % MgO-doped LiNbO3 with a multiple-channel structure design and pumped by a compact diode-pump solid-state laser operating at 1.064 μm. Wide tunability from 1.44 to 1.58 μm at the signal beam wavelength and from 3.28 to 4.11 μm at the idler beam wavelength was achieved by both varying the temperature and translating the crystal through the resonator and the pump beam with no realignment required. The tuning performance and its related factors were analyzed, and at the same time the output performance as well as the effect of mid-infrared absorption of idler beam was investigated. [ABSTRACT FROM AUTHOR]

In this letter we report the experimental result on the study of light scattering in a one-dimensional quasiperiodically poled LiTaO3 crystal. The infrared scattering signal in the crystal was upconverted into visible band by sum frequency with incident light, forming a set of coaxial conical second harmonic beam with a quasiperiodic ratio at the radius. The quasi-phase-matching significantly enhanced such a nonlinear interaction. The angular distribution of scattering light in crystal was extracted from the experimental result. This reveals a possible application of quasiperiodic structure on the study of light scattering. [ABSTRACT FROM AUTHOR]

We report a quasi-white-light laser, which was generated by an all-solid-state laser technique. The approach is to use a cascaded optical superlattice in a LiTaO3 crystal to directly frequency double and triple a diode-pumped, Q-switched dual-wavelength Nd:YVO4 laser. Three primary color lights, red at 671 nm, green at 532 nm, and blue at 447 nm, were simultaneously generated in a proper proportion, forming a quasicontinuous, quasi-white-light laser with a maximum output power of 530 mW under a pump power of 18 W. From the result, a more effective quasi-white-light output can be anticipated if the superlattice is fabricated in a stoichiometric LiTaO3 crystal and the double resonant technique is further optimized. [ABSTRACT FROM AUTHOR]

A compact, pulsed, red, green, and blue laser source based on cascaded quasi-phase-matched wavelength conversion in two periodic superlattices set in tandem in a single stoichiometric LiTaO3 crystal and pumped by a laser source at 532 nm is reported. The white light equivalent flux obtained was 80 lm per 1 W input with a green to white light power conversion efficiency of >30%. Unity power conversion is feasible in this monolithic approach. [ABSTRACT FROM AUTHOR]

We report a compact all-solid-state mid-infrared optical parametric oscillator with wide tunability using periodically poled 5 mol % MgO-doped LiNbO3 with a multiple-channel structure design and pumped by a compact diode-pump solid-state laser operating at 1.064 μm. Wide tunability from 1.44 to 1.58 μm at the signal beam wavelength and from 3.28 to 4.11 μm at the idler beam wavelength was achieved by both varying the temperature and translating the crystal through the resonator and the pump beam with no realignment required. The tuning performance and its related factors were analyzed, and at the same time the output performance as well as the effect of mid-infrared absorption of idler beam was investigated. [ABSTRACT FROM AUTHOR]

MYBA2 transcription factor (Myb-related gene) affects the coloring in grapevine berry and plays an important role in the biosynthesis of anthocyanin. The MYBA2 gene was cloned from Vitis vinifera L. cv. Cabernet Sauvignon and polyclonal antibodies for VvmybA2 were prepared. The VvmybA2 gene expression patterns were observed in seven tissues (the leaf, stem, flower, bud, root, berry, and tendril) and during the berry development stage at transcriptional and translational levels, respectively. The results indicated that the expression of VvmybA2 was approximately 11-fold higher in the berry than that in the other six tissues, and increased rapidly from 60 days after full bloom reaching a maximum on day 80. Furthermore, both the anthocyanin content and UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT) gene expression levels increased rapidly 60 days after full bloom. Moreover, correlation analysis indicated that the transcriptional and translational expression levels of the VvmybA2 gene were significantly positively correlated with not only UFGT and DFR genes but also with the anthocyanin content during berry development. These results suggested that VvmybA2 could not only regulate the transcription of both UFGT and DFR but also is involved in the expression of the UFGT gene associated with color determination in grape berries.

We study nonlinear Cerenkov radiation generated from a nonlinear photonic crystal waveguide where the nonlinear susceptibility tensor is modulated by the ferroelectric domain. Nonlinear polarization driven by an incident light field may emit coherently harmonic waves at new frequencies along the direction of Cerenkov angles. Multiple radiation spots with different azimuth angles are simultaneously exhibited from such a hexagonally poled waveguide. A scattering involved nonlinear Cerenkov arc is also observed for the first time. Cerenkov radiation associated with quasi-phase matching leads to these novel nonlinear phenomena.

We demonstrate a high-power red-green-blue laser source based on the quasi-phase-matching and intermittent oscillating dual-wavelength laser technique. A cascaded LiTaO3 superlattice was used to achieve the generation of red light at 660 nm, green light at 532 nm, and blue light at 440 nm to obtain the output of red-green-blue laser light from a diode-side-pumped Q-switched intermittent oscillating dual-wavelength Nd:YAG laser. The average output power of red-green-blue of 1.01 W was achieved under the total fundamental power of 5.1 W, which corresponds to the conversion efficiency of 20%.

A high-power 532 nm-pumped multikilohertz nanosecond optical parametric oscillator using a periodically poled 1.0 mol.% MgO-doped stoichiometric lithium tantalate crystal that could be operated from room temperature to 200 degrees C without damage is reported. A broad continuous tuning range from 855 to 1410 nm was achieved within a single domain period. Efficient operation of high peak power and watt level average power with a power conversion of 62.5% was measured. These results show that a high-resolution high average power visible tunable source can be realized.

A compact, efficient optical parametric oscillator (OPO) for the visible to near-infrared region based on periodically poled stoichiometric lithium tantalate pumped by a frequency-doubled multikilohertz Q-switched Nd:YAG laser is demonstrated. Up to 61% photon conversion with a 71% slope efficiency for photon conversion from 532 nm to the signal radiation was measured. We observed that the efficient conversion diminished the potential for photorefractive damage induced by the 532 nm radiation in the crystal and made sustained operation of the OPO device possible.

Aim: To study the palliative treatment of malignant obstruction of digestive tract with placement of intraluminal stent combined with intra-arterial infusion of chemotherapeutic drugs., Methods: A total of 281 cases of digestive tract malignant obstruction were given per oral (esophagus, stomach, duodenum and jejunum), per anal (colon and rectum) and percutaneous transhepatic (biliary) installation of metallic stent. Among them, 203 cases received drug infusion by cannulation of tumor supplying artery with Seldinger's technique., Results: Altogether 350 stents were installed in 281 cases, obstructive symptoms were relieved or ameliorated after installation. Occurrence of restenotic obstruction was 8-43 weeks among those with intra-arterial drug infusion, which was later than 4-26 weeks in the group with only stent installation. The average survival time of the former group was 43 (3-105) weeks, which was significantly longer than 13 (3-24) weeks of the latter group., Conclusion: Intraluminal placement of stent combined with intra-arterial infusion chemotherapy is one of the effective palliative therapies for malignant obstruction of the digestive tract with symptomatic as well as etiological treatment.