Optical communications make use of light waves, very high frequency (100 terahertz) electromagnetic waves, for information transmission. Modern optical communications were begun in the 1960s, when lasers were invented as a coherent light source. Since then, the rapid development of photonic technologies has made possible optical communication links with a …

We see things because our eyes are sophisticated light detectors: they constantly capture the light rays bouncing off nearby objects so our brain can construct an ever-changing impression of the world around us. When our eyes see a three-dimensional image such as apple, Light reflects off the surface of the apple …

Quantum key distribution (QKD), establishes highly secure keys between distant parties by using single photons to transmit each bit of the key. A unique aspect of quantum cryptography is that Heisenberg’s uncertainty principle ensures that any attempts to intercept and measure quantum transmissions, will introduce an anomalously high error rate …