We present a two stage Inverse Free Electron Laser accelerator proposed for construction at the UCLA Neptune Lab. Proof-of -principle experiments on the IFEL scheme have been carried out successfully. This experiment is intended to achieve a 100 MeV energy gain, staging two IFEL modules. It will use a 16 MeV electron beam, a 1 TW CO2 laser and two different tapered helical undulators. The probl...

Aged oxide-defined narrow-stripe lasers sometimes exhibit beam narrowing in both the near-field and far-field light distributions, accompanied by the development of sustained pulsations. The beam narrowing is found to correlate with the presence of a darkened area under the stripe viewed by cathodoluminescence imaging. We propose an explanation based on a thermal waveguiding effect resulting fr...

In the traditional laser beam quality measurement, the lens transform method is used to obtain the information of the multi spot, and can only evaluate the beam quality of a continuous or high repetition rate laser, the evaluation speed is slow and the real-time performance is poor. A micro lens array method is proposed, which samples the laser spot only once and obtains all the spot informatio...

Directional dithering of a laser beam potentially limits the detection accuracy of a laser triangulation displacement probe. A theoretical analysis indicates that the measurement accuracy will linearly decrease as the laser dithering angle increases. To suppress laser dithering, a scheme for reduction of the influence of laser beam directional dithering in a laser triangulation displacement pro...

Directional dithering of a laser beam potentially limits the detection accuracy of a laser triangulation displacement probe. A theoretical analysis indicates that the measurement accuracy will linearly decrease as the laser dithering angle increases. To suppress laser dithering, a laser triangulation displacement probe with laser beam pointing control, which consists of a collimated red laser, ...

Self-mixing laser sensors require few components and can be used to measure velocity. The self-mixing laser sensor consists of a laser emitting a beam focused onto a rough target that scatters the beam with some of the emission re-entering the laser cavity. This 'self-mixing' causes measurable interferometric modulation of the laser output power that leads to a periodic Doppler signal spectrum ...

Laser beam forming is a novel technique developed for the joining of metallic components. In this study, an overview of the laser beam forming process, areas of application, the basic mechanisms of the laser beam forming process, some recent research studies and the need to focus more research effort on improving the laser-material interaction of laser beam forming of titanium and its alloys ar...

A novel scheme of transferring cold atoms in a double magneto-optical trap (MOT) system has been experimentally demonstrated. Cold cesium atoms trapped in a vapor-cell MOT are efficiently transferred to an ultrahigh-vacuum (UHV) MOT by a continuous-wave divergent Gaussian transfer laser beam. When large red detuning and moderate intensity are adopted for the transfer laser beam, enhancement of ...

We have been investigating the influence of atmospheric turbulence on the propagation of a picosecond laser pulse. The figure of merit of presented results is the time of propagation, its absolute delay and jitter. Phase wavefront deformation or beam profile changes were not studied. The correlation of the atmospheric turbulence with the propagation delay fluctuation was measured. The research ...