White light interferometry (WLI) is a contact-free optical method for measuring surface height. It uses the phase difference between the light reflected off a reference mirror and the target sample to ...

A surprising trick that allows a beam of light to be completely absorbed even in the thinnest of layers: Using mirrors and lenses, a 'light trap' can be constructed, in which the light beam is steered ...

Researchers have built a paper-thin chip that converts infrared light into visible light and directs it precisely, all without mechanical motion. The design overcomes a long-standing efficiency-versus ...