Session Index

Table-top hard X-ray sources have drawn significant attention recently. Betatron radiation, one of the X-ray sources, is expected to be an alternative to large synchrotron radiation facilities. In this study, the experimental condition of high brightness and polarized X-ray using the NCU 100 TW laser system is evaluated numerically. Simulations show that the shock-front injection electrons produce electrons with high peak energy and a low energy spread. By tilted shock front (TSF) [1,2], electrons injected from one side of the plasma wave significantly increase; their coherence is also enhanced. And, the electron beam is expected to generate polarized X-rays.

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The conversion efficiency of laser-produced plasma (LPP) extreme ultraviolet (EUV) is a crucial issue for the semiconductor industries (e.g. TSMC, ASML) which requires high power EUV light source. The one-dimensional simulation framework is developed that integrate the plasma simulation code MEDUSA with atomic model and radiative transport equation. The framework is based on multiple time scales and employs quasi-equilibrium assumption. We discover an empirical equation relating to the laser wavelength using a parametric study of the incident laser and propose a simple physical explanation.

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We present the study of the formation of conjugated resonator in the circular ring laser diode by the excitation of conjugated reflection due to enhanced optical nonlinearity of the quantum wells material and the strong laser emission in the circular ring resonator. The circular ring laser diode is consisted by a ridge waveguide circular ring resonator and a Y- junction coupler. Measurements of the mode spacing of the laser emission from the Y-junction output coupler and the soliton waveguide terminal were fit with the calculated length of the resonator.

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We model the cross-relaxation mechanism in a thulium Q-switched ytterbium-doped all-fiber fiber laser using a set of rate equations. The results reveal that a strong cross relaxation in a highly Tm-doped fiber is preferable for stabilizing Q-switching operation and preventing the system from deteriorating to CW lasing.

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A pulsed vortex laser formed by coherent superposition of off-axis resonating traveling waves was built in an azimuthal symmetry breaking laser cavity with an intra-cavity spiral phase element. Sub-ns pulse as a result of mode coupling of the longitudinal modes spectrally separating by one free spectral range was observed in addition to periodic and chaotic oscillation under passive Q-switched operation.

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Simultaneous multi-peak in orange-yellow band laser source was demonstrated by using intra-cavity second harmonic generation technique on periodically-poled-lithium-tantalate (PPLT). Our design showed the efficiency of the sum frequency generation of two idlers was comparable with second harmonic generation of each idler.

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We report fs laser direct writing waveguides in z-cut MgO-doped congruent lithium niobate crystal. The propagation loss in different processing parameters including laser pulse energy, and pattern distribution were studied. A 1064 nm DFB laser was adopted to characterize the guiding performances and the propagation loss was measured in the range of 2~6 dB/cm.

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High-order modes are generated by using a selectively off-axis pumped Nd:YVO4/KGW Raman lasers with intracavity second-harmonic generation (SHG) at 588 nm. Various structured lights are produced by converting the High-order modes through an astigmatic mode converter (AMC). The experimental results of the propagation for the High-order modes conversion are theoretically analyzed, and the phase structure is numerically calculated to confirm the robustness of the optical vortices.

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We investigated the polarization properties of scattering light from the KGd(WO4)2 crystal by the use of linearly polarized incident light. The polarization characteristics at Raman shifts of 768cm-1 and 901cm-1 vary with the angle between the incident light and the KGW crystal.

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Controlling emission properties of a quantum emitter (atom, fluorophore, quantum dot, etc.) through optical cavities is a central topic in cavity-QED. Here, our fabrication process provides a stable platform consisting of fluorophores and a plasmonic nanocavity. The emission property of this system is complicated. Polariton emission, resonant Raman scattering, surface-enhanced fluorescence can be observed depending on the coupling strength and the excitation wavelength.

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In this study, thermal characteristics of high power 940nm flip-chip vertical cavity surface emitting laser (VCSEL) array with different heat sink is investigated. According to the measurement results of wavelength to temperature dependence of the flip-chip VCSEL array, copper heat sink with an additional diamond-like carbon (DLC) coating can help to promote heat dissipation of VCSEL array during operation and obtain better wavelength to temperature stability than using conventional copper heat sink. The wavelength to temperature dependence can be as low as Δλ/ΔT=0.0486 nm/K.

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In this paper, nonlinear dynamics of the period-one dynamic generated by the optical feedback and polarized optical feedback are discussed in numerical simulations. The period-one dynamic obtained by polarization rotated feedback system show better performances by compared with those generated by traditional optical feedback system when the polarization angles and bias currents are properly adjusted. Moreover, the detailed characteristics in different operational parameters are also discussed.

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We design a fiber-optic cavity based on semiconductor optical amplifier gain medium. As the continuous-wave lasing phenomenon results from the stimulated amplification of photons at the frequencies close to the peak of intracavity net gain, the observation of narrowing and redshift of the spectrum by tuning pump current that may signature the formation of photon BEC.

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A direct laser patterning process was proposed to prepare transparent organic photovoltaics (OPVs) with high power conversion efficiency (PCE). Besides the transparency of the devices, the device’s PCE was also kept at over 10%. As a result, such a process can pattern the feature of the OPV, which tunes the transmittance value according to its patterned shape. We believe that our proposed device can achieve the average visible transmission value of > 70% if we reduce the pattern space with a micro-scale.

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