The idea of guiding light through hollow pipes dates to the 19th century, but solid-core fibers made much better optical waveguides. Now the emerging technology of hollow-core fibers has resurrected an old idea.
IMAGE OF THE WEEK
In a simple educational demonstration to show the wave nature of light, an Arago spot is visualized with a laser pointer and a chainlet. The photo was taken with a cellphone, and the laser beam was expanded with a diverging lens.
View more »