Recent progress of optical waveform synthesis technology has brought the generation of isolated single-cycle pulses within our reach. In particular, such a light source becomes important for latest high-field physics. To exploit the full potential of such a single-cycle pulse, it is highly important to characterize the complete waveform of the single-cycle pulse, namely, how the electric field oscillates in the pulse. Recently, we proposed a novel pulse characterization scheme, which enables us to determine not only the intensity and (relative) phase profiles of ultrashort pulses but also their absolute carrier-envelope phase values. The method is based on a combination of frequency-resolved optical gating and electro-optic sampling, which can be extended to a self-referencing scheme to determine the electric field oscillation of few-cycle ultrashort pulses. We have experimentally demonstrated the technique to characterize sub-cycle mid-infrared pulses, and numerically studied the capability of the scheme to incorporate a self-referencing technique and to extend the wavelength range to visible region.In this presentation, we plan to show the detail of the concept of the waveform characterization scheme.

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we report a 50 W peak-power Terahertz wave from optical parametric generation with a 1064-nm microchip laser pump in a y-cut LiNbO3 crystal. The experimental results demonstrate the THz source consists of a gain medium and an off-axis THz oscillator has high efficiency.

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Optical injection can induce period-one nonlinear dynamics in semiconductor lasers, resulting in continuously tunable microwave generation from a few to tens and hundreds of gigahertz. Optical feedback can stabilize generated microwaves, leading to reduction of microwave linewidth. Stable and tunable microwave generation is feasible using nonlinear dynamics of semiconductor lasers.

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The metal-GaN spiral cavity laser with the high circular dichroism was demonstrated at room temperature. The lasing action was observed at a ultra-violet wavelength of approximately 363 nm with a low threshold power density. The high dissymmetry factor +1.4 of the metal spiral cavity lasers was observed in experiment.

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We study the unidirectional photoluminescence emission from gold Yagi-Uda nanoantenna by Fourier imaging and confocal scanning photoluminescence imaging technique. In addition, we show a novel design of L-shape Yagi-Uda antenna with two working frequency that unidirectionally guide two different photoluminescence wavelength toward two orthogonal direction.

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