Hybrid laser processing for precision microfabrication of hard materials, in which the interaction of a conventional pulsed laser beam and another medium on the material surface leads to effective ablation, is reviewed. The main role of the medium is to produce strong absorption of the nanosecond laser beam by the materials. Simultaneous irradiation with the ultraviolet (UV) laser beam and the ...

the standards of endodontics have constantly been raised in the last 25 years by practitioners’ researches and their interest. most of the scientists believe the recent developments and the use of lasers as the most exciting achievement in endodontic treatment. nowadays, lasers are being used in endodontics to improve the prognosis of the root-filled teeth. the implement of suitable wavelengths...

The thermal emittance and temporal response of a photocathode set an upper limit on the maximum achievable electron beam brightness from a photoemission electron source, or photoinjector. We present measurements of these parameters over a broad range of laser wavelength for two different negative electron affinity NEA photocathodes. The thermal emittance of NEA GaAs and GaAsP has been measured ...

Due to sensitive and important applications of free-electron laser in industry and medicine, improvement of the power and efficiency of laser has always been emphasized. Therefore, understanding the created field and examining the properties of the field in waveguides with different shapes and studying the sustainability of electrons movement are particularly important. In this study, the beh...

Since 2006, we have been developing a novel photocathode gun gated by the laser-induced Schottkyeffect. This new type of gun utilizes laser coherency to aim at a compact femtosecond laser oscillator as an IR laser source using Z-polarization on a metal photocathode. This Z-polarization scheme reduces the laser photon energy to excite the cathode with a longer wavelength by reducing its work fun...

A photocathode-based low-emittance femtosecondbunch electron source is developed in Osaka University to reveal the hidden dynamics of intricate molecular and atomic processes in materials through experimentation such as time-resolved pulse radiolysis or time-resolved electron diffraction. The transverse and longitudinal dynamics of femtosecond electron beam in the photocathode rf gun were studi...

We report bunching, slowing, and acceleration of a supersonically cooled beam of diatomic hydroxyl radicals (OH). In situ observation of laser-induced fluorescence along the beam propagation path allows for detailed characterization of longitudinal phase-space manipulation of OH molecules through the Stark effect by precisely sequenced inhomogeneous electric fields.

Laser footprint size and beam divergence angle tuning was found to affect LiDAR data accuracy and measurement precision because of beam axis shifting. The laser beam divergence angle is generally tunable in modern LiDAR systems in order to adapt to different application scenarios. Beam divergence angle can either be switched from one position to the other (i.e. 0.3mRad / 0.8 mRad), or be tuned ...