A California startup wants to bounce sunlight from orbit onto Earth after dark, and the idea is stirring up serious debate. Supporters picture brighter nights for emergencies and extended productivity ...

Light can carry angular momentum in two distinct ways. One comes from polarization, which describes how the electric field ...

The experiment also showed that tuning the light beam controlled the propulsion—the stronger the laser, the greater the ...

Most laser sources produce Gaussian beams that diverge as they propagate. This natural spreading limits their effectiveness in applications that require light to remain concentrated over long ...