See the light

The aurora borealis, or “northern lights,” and its cousin STEVE (strong thermal emission velocity enhancement) paid a colorful visit to the northern midlatitudes on 23 March, as shown in this photo taken just outside of Bozeman, Montana, by Joseph Shaw. STEVE, which was first identified as an optical phenomenon separate from the aurora borealis in 2016, has a broader-bandwidth optical emission spectrum. In contrast, the aurora borealis (seen on the left-hand side and on the bottom of the STEVE arc in this photo) contains largely green and red atomic emission lines of oxygen and nitrogen excited by energetic particles from the Sun. STEVE often appears at lower latitudes than the aurora borealis, so watch carefully! Photo by: Joseph Shaw The beauty of optics and photonics based technology can be seen in light-based art installations, laser shows, public lighting, and natural phenomena. Submit an image of photonics in society from your hometown or travels, and it may be featured in a future issue of Photonics Focus. Submissions can be sent to: @SPIEtweets on Twitter, @SPIEphotonics on Instagram, or by email to photonicsfocus@spie.org.