Wiktionary
lightwave
n. A wave of light.
Wikipedia
Lightwave (band)
Lightwave is the ambient music project of keyboardists Christoph Harbonnier and Christian Wittman, founded in 1984 in Paris, France. They have collaborated with a plethora of artists, such as Hector Zazou, Michel Redolfi, Jon Hassell and Paul Haslinger.
Usage examples of "lightwave".
Milky Way, the cruiser hurtled at a speed which a sentient lightwave would find meaningless.
Of course if we find a method of capturing the lightwaves hurtling through space and reconstructing the original picture, then a simulated time trip would be possible.