KTA-OPO for 1742 nm laser generation driven by a composite Nd:YVO-based self-Raman laser.

In this work, a double-end diffusion bonded Nd:YVO self-Raman laser was designed to drive an intracavity, noncritically-phase-matched KTiOAsO (KTA) optical parametric oscillator (OPO). Both conversion efficiency and output power at 1.7 µm (the wavelength of the OPO signal field) were improved by effectively reducing the thermal lens effect and increasing the effective length of self-Raman medium.

Decoupling bulk and surface characteristics with a bare tilted fiber Bragg grating.

The tilted fiber Bragg grating (TFBG) with dense comb-like resonances offers a promising fiber-optic sensing platform but could suffer from cross sensitivity dependent on bulk and surface environment. In this work, the decoupling of bulk and surface characteristics (indicated by bulk refractive index (RI) and surface-localized binding film) from each other is attained theoretically with a bare TFBG sensor. This is realized with the proposed decoupling approach based on differential spectral responses of cut-off mode resonance and mode dispersion represented as wavelength interval between P- and S-polarized resonances of the TFBG to the bulk RI and surface film thickness.

Realization of thousand-second improved confinement plasma with Super I-mode in Tokamak EAST.

Mastering nuclear fusion, which is an abundant, safe, and environmentally competitive energy, is a great challenge for humanity. Tokamak represents one of the most promising paths toward controlled fusion. Obtaining a high-performance, steady-state, and long-pulse plasma regime remains a critical issue.

Performance improvement of space-resolved extreme ultraviolet spectrometer by use of complementary metal-oxide semiconductor detectors at the Experimental Advanced Superconducting Tokamak.

Two pairs of space-resolved extreme ultraviolet (EUV) spectrometers working at 5-138 Å with different vertical observation ranges of -7 ≤ Z ≤ 19 and -18 ≤ Z ≤ 8 cm have been newly developed to observe the radial profile of impurity line emissions and to study the transport of high-Z impurity ions intrinsically existing in EAST tokamak plasmas. Both spectrometers are equipped with a complementary metal-oxide semiconductor (CMOS) detector (Andor Marana-X 4.2B-6, Oxford Instruments) with sensitive area of 13.

Simultaneous generation and real-time observation of loosely bound solitons and noise-like pulses in a dispersion-managed fiber laser with net-normal dispersion.

We demonstrate the coexisting dynamics of loosely bound solitons and noise-like pulses (NLPs) in a passively mode-locked fiber laser with net-normal dispersion. The total pulse number of the single soliton bunch under the NLP operation regime almost increases linearly with increasing pump power, whereas the average pulse spacing decreases accordingly. Furthermore, pulse-to-pulse separation between adjacent soliton pulses in one soliton bunch keeps in the range of hundreds of picoseconds, which decreases from left to right with the change of time.

YVO cascaded Raman laser for five-visible-wavelength switchable emission.

We report switchable emission of visible light at five wavelengths generated in a $\text{YVO}_4$YVO cascaded Raman cavity driven by an acousto-optic ${Q}$Q-switched Nd:YAP laser at 1080 nm. The second-harmonic generation and sum-frequency generation of the fundamental, first-Stokes, and second-Stokes waves were realized based on the angle-tuned BBO crystal. The phase-match angle tuning span of a BBO crystal is only approximately 2.

Compact passively Q-switched RbTiOPO cascaded Raman operation.

Compact passively Q-switched RbTiOPO cascaded Raman laser operation has been investigated for the first time, to our knowledge. A Nd:YAG/Cr:YAG composite crystal was adopted for passively Q-switched fundamental laser generation. 440 mW multi-Stokes laser output with X(ZZ)X configuration according to the Porto notations was achieved under the incident pump power of 10 W.

Collisional dynamics in laser-induced plasmas: evidence for electron-impact excitation.

We have experimentally investigated the collisional dynamics in femtosecond-laser-induced plasmas and presented the evidence for electron-impact excitation through enhanced high-order harmonic (HH) generation. The measurements were carried out by using an elliptically polarized pump pulse to induce the underdense plasmas and by using a time-delayed linearly polarized probe pulse to drive the HH generation from the plasmas. We found that the rise time of this enhanced HH generation was insensitive to the ellipticity degree (ED) of pump pulse but sensitive to its laser intensity (LI).

Efficient 1.7 μm light source based on KTA-OPO derived by Nd:YVO self-Raman laser.

An intra-cavity optical parametric oscillator (OPO) emitting at 1.7 μm derived by Nd:YVO self-Raman laser is demonstrated in this Letter, with a KTiOAsO (KTA) crystal used as nonlinear optical crystal. A laser diode end-pumped acousto-optic Q-switched Nd:YVO self-Raman laser at 1176 nm was employed as the pump source.

Compact self-cascaded KTA-OPO for 2.6 μm laser generation.

We reported a compact self-cascaded KTA-OPO source for 2.6 μm coherent light generation. The OPO is driven in a diode end-pumped and Q-switched Nd:YVO laser cavity.

RbTiOPO cascaded Raman operation with multiple Raman frequency shifts derived by Q-switched Nd:YAlO laser.

An intra-cavity RbTiOPO (RTP) cascade Raman laser was demonstrated for efficient multi-order Stokes emission. An acousto-optic Q-switched Nd:YAlO laser at 1.08 μm was used as the pump source and a 20-mm-long x-cut RTP crystal was used as the Raman medium to meet the X(Z,Z)X Raman configuration.

Efficient laser operation based on transparent Nd:LuO ceramic fabricated by Spark Plasma Sintering.

Efficient laser operation of Nd:LuO ceramic fabricated by Spark Plasma Sintering (SPS) was demonstrated. Transparent Nd:LuO ceramic was successfully fabricated by Spark Plasma Sintering and its laser experiment was done. On the F to I transition, the obtained maximum output is 1.

2-D soft x-ray arrays in the EAST.

A high spatial and temporal resolution soft x-ray (SXR) imaging diagnostic has been installed in EAST for the study of magnetohydrodynamics activities and core high-Z impurity transport. Up to 122 lines of sight view the poloidal plasma from three directions (two up-down symmetrical horizontal arrays and one vertical array), which renders the diagnostic able to provide detailed tomographic reconstructions under various conditions. Fourier-Bessel method based on flux coordinates was employed for 2-D SXR tomographic reconstruction.

[Application of Extreme-Ultraviolet Ar Spectra Analysis in the Study of Divertor Impurity Screening in EAST Tokamak].

Divertor impurity injection on Tokamak is the most important means to achieve divertor impurity screening efficiency. In this paper, a fast-response extreme-ultraviolet (EUV) spectrometer is used to monitor the Ar emission lines during the EAST(Experimental Advanced Superconducting Tokamak)divertor Ar injection experiment. Based on the NIST(National Institute of Standards and Technology)atomic spectrum database, the emission lines from different ionized Ar ions in 2～50 nm wavelength range, e.

Comparison of 1.15 µm Nd:YAG\KTA Raman lasers with 234 and 671 cm shifts.

Nd:YAG/KTA intra-cavity Raman lasers with two different Raman shifts are experimentally compared for eradiating around 1.15 µm. The different Raman processes are attributed to polarization dependent Raman gain of KTA crystal and nearly linear polarization of Nd:YAG fundamental light with Q-switch operation.

Multi-order Stokes output based on intra-cavity KTiOAsO₄ Raman crystal.

We report efficient multi-Stokes Raman output of a KTiOAsO4 (KTA) crystal driven by a laser diode end-pumped acousto-optic Q-switched Nd:YAG laser. The Raman outputs of two x-cut KTA crystals, one with a length of 20 mm and the other one of 25-mm, were experimentally compared. Under an incident pump power of 10.

Efficient RTP-based OPO intracavity pumped by an acousto-optic Q-switched Nd:YVO₄ laser.

This Letter describes an intracavity pumped optical parametric oscillator (OPO) based on noncritical phase matching RbTiOPO4 (RTP) crystal driven by a laser diode end-pumping acousto-optic Q-switched Nd:YVO4 laser. Simultaneous efficient signal light at 1.6 μm and idler light at 3.

Laser operation of diode-pumped Er,Yb co-doped YAG ceramics at 1.6 μm.

1.6 μm eye-safe emission of a diode pumped Er,Yb co-doped YAG ceramic laser is firstly demonstrated. Operation of the ceramic laser under different ceramic sample lengths, co-doping concentrations and control temperatures were experimentally investigated.

Potential sodium D2 resonance radiation generated by intra-cavity SHG of a c-cut Nd:YVO4 self-Raman laser.

Intra-cavity frequency doubling with 589 nm emission from a compact c-cut Nd:YVO4 crystal self-Raman laser was investigated. A 15-cm-length LBO with non-critical phase-matching cut (θ = 90°, ϕ = 0°) was used for efficient second-harmonic generation. At a pump power of 16.

Efficient second harmonic generation of double-end diffusion-bonded Nd:YVO4 self-Raman laser producing 7.9 W yellow light.

A high power and efficient 588 nm yellow light is demonstrated through intracavity frequency doubling of an acousto-optic Q-switched self-frequency Raman laser. A 30-mm-length double-end diffusion-bonded Nd:YVO(4) crystal was utilized for efficient self-Raman laser operation by reducing the thermal effects and increasing the interaction length for the stimulated Raman scattering. A 15-mm-length LBO with non-critical phase matching (theta = 90 degrees, phi = 0 degrees) cut was adopted for efficient second-harmonic generation.

High-efficiency intracavity Nd:YVO4\KTA optical parametric oscillator with 3.6 W output power at 1.53 microm.

An efficient intracavity KTA optical parametric oscillator (OPO) driven by diode-end-pumped acousto-optical Q-switched Nd:YVO(4) laser is demonstrated. The mode mismatch between fundamental cavity and OPO cavity caused by the thermal lens effect in Nd:YVO(4) crystal as the pump power increased was studied. To lessen mode mismatch, a thermal lens-like cavity mirror made of plane BK7 glass induced by idler absorption was introduced into the OPO cavity.

Yellow-light generation of 5.7 W by intracavity doubling self-Raman laser of YVO(4)/Nd:YVO(4) composite.

A high-power 588 nm light produced by an intracavity frequency-doubling acousto-optic Q-switched self-frequency Raman laser is reported. A 20-mm-long YVO(4)/Nd:YVO(4) composite crystal and a 15-mm-long LiB(3)O(5) (LBO) with noncritical phase-matching (theta=90 degrees , phi=0 degrees ) cut were adopted for efficient self-Raman laser operation and second-harmonic generation, respectively. By the optimizing the focus position of incident pump light and Q-switch repetition rate, yellow light with 5.