optics

Humanity’s desire to measure time more and more accurately has been a driving force in technological development, and improved clocks and the innovations behind them have repeatedly delivered unexpected applications and scientific discoveries. For instance, when sailors needed high precision timekeeping to better navigate the open seas, it motivated the development of mechanical clocks. And in turn, more accurate clocks allowed better measurements in astronomy and physics. Now, clocks are inescapable parts of daily life, but the demands of GPS, space navigation and other applications are still motivating scientists to push timekeeping to new extremes.

Optical fibers are hair-like threads of glass used to guide light. Fibers of exceptional purity have proved an excellent way of sending information over long distances and are the foundation of modern telecommunication systems. JQI researchers in collaboration with scientists from the Naval Research Laboratory have developed a new technique for visualizing light propagation through an optical nanofiber, detailed in a recent Optica paper. The result is a non-invasive measurement of the fiber size and shape and a real-time view of how light fields evolve along the nanofiber. Direct measurement of the fields in and around an optical nanofiber offers insight into how light propagates in these systems and paves the way for engineering customized evanescent atom traps.  

Color is strange, mainly due to perception. Setting aside complex brain processes, what we see is the result of light absorption, emission, and reflection. Trees appear green because atoms inside the leaves are emitting and/or reflecting green photons. Semiconductor LED brake lights emit single color light when electrical current passes through the devices.