We demonstrate an electrostatic surface guiding for cold polar molecules over a long distance of 44.5 cm, 0.85 mm above a dielectric substrate, and measure the transverse distribution of the guided supersonic D2O/CH3Br beam and its longitudinal velocity one. Also, we study the dependence of the relative guiding efficiency and the transverse temperature of the guided molecular beam on the guiding voltage, and show that the absolute guiding efficiencies from the Monte Carlo simulation and theoretical calculation multiplied by 3 are about equal to the measured relative one.

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We reported three types of complex micro/nanostructures on 6H-SiC crystal induced by the interferences of three femtosecond laser beams by arranging three types of laser polarization combinations. The micro/nanostructures are composed of two parts: two-dimensional long-periodic micropatterns determined by the interferential intensity pattern and short-periodic nanopatterns determined by the interferential polarization pattern. Theoretical calculation indicates that the different polarization combinations will lead to a distinct complex interferential polarization pattern and intensity pattern, and they accord well with the experimental results.

Femtosecond laser fabrication outperforms the traditional fabrication techniques with high precision, high efficiency, low collateral damage and wide applicability, which has shown to be a powerful tool in precision machining. Imaging the ultrafast dynamics of femtosecond laser fabrication is necessary for understanding the processing mechanism and for establishing the corresponding physical models. Up to now, ultrafast measurement techniques based on the pump−probe strategy are the most used methods. However, they are limited by laser energy stability and materials surface uniformity, which have a heavy impact on the dynamic measurement precision of femtosecond laser fabrication. To overcome this limitation of the traditional pump−probe techniques, we developed chirped spectral mapping ultrafast photography (CSMUP), which can achieve single-shot real-time ultrafast imaging with a frame rate of about 250 billion frames per second (temporal frame interval of 4 ps) and a spatial resolution of less than 833 nm. We experimentally imaged the dynamics of femtosecond laser ablation in silicon under a 400 nm femtosecond laser exposure with CSMUP, and the experimental result agreed well with previous theoretical models. CSMUP provides a new strategy to improve the efficiency and accuracy of femtosecond laser fabrication by a single-shot dynamic measurement of the interaction between the femtosecond laser and materials, and it is expected to work as a real-time detection method for various ultrafast phenomena.

We experimentally demonstrate a controllable electrostatic beam splitter for guided ND3 molecules with a single Y-shaped charged wire and a homogeneous bias field generated by a charged metallic parallel-plate capacitor. We study the dependences of the splitting ratio R of the guided ND3 beam and its relative guiding efficiency η on the voltage difference between two output arms of the splitter. The influences of the molecular velocity v and the cutting position L on the splitting ratio R are investigated as well, and the guiding and splitting dynamic processes of cold molecules are simulated. Our study shows that the splitting ratio R of our splitter can be conveniently adjusted from 10% to 90% by changing ΔU from -6  kV to +6  kV, and the simulated results are consistent with our experimental ones.