WiFi is embedded in our lives today. The term originated about four decades ago (as a marketing ploy, designed to rhyme with the term “Hi-Fi”) and has revolutionized personal communications, internet ...

An LED and a semiconductor laser (or laser LED) work in essentially the same way, that is, light is emitted as electrons and holes combine, with emission wavelength dependent upon the materials used.

Researchers have found that under certain conditions, a laser beam can act like an opaque object and cast a shadow, opening new possibilities for technologies that could use a laser beam to control ...