When the first laser was demonstrated by Ted Maiman in 1960, thus proving a theory of stimulated emission published in 1958 by Nobel Prize winners Arthur Schawlow and Charles Townes, scientists were surprised and not sure what to do with this new technology, according to Townes. In A Century of Nature: Twenty-One Discoveries that Changed Science and the World, Townes says that in those early days he was frequently teased that lasers were “a solution looking for a problem.” That obviously didn’t last long, because by 1962 Bob Hall had invented the semiconductor laser, which rapidly spawned a whole host of commercial applications.
In the decades that followed Maiman’s first demonstration, laser fever consumed the public’s imagination (Death rays! Light sabers!). Scientists, on the other hand, just wanted to learn as much as they could about this new technology. Like, for example, what materials could be made to lase?
In 1970, Schawlow and his postdoc (and future Nobel laureate), Theodor Hänsch, famously decided to try to make Jell-O lase. They tried twelve different flavors and couldn’t get it to work, but ultimately succeeded with clear gelatin and a bit of sodium fluorescein dye—a “nearly” nontoxic edible laser.
In 1975, three scientists with the National Bureau of Standards in Boulder, Colorado tried—and succeeded—to produce a weak laser line with vodka, gin, and rum, which they wrote about in the IEEE Journal of Quantum Electronics. In a bit of humor rare to scholarly writing, the scientists conclude, “It is quite obvious that there are better uses of ethyl alcohol.”
These early (and fun) experiments seem to reinforce Art Schawlow’s pronouncement to Hänsch that “anything will lase if you hit it hard enough!”
In the decades since Maiman’s 1960 demonstration of the ruby laser, scientists have figured out what to do with lasers many times over. And yet, many ideas in laser science are still in the exploration stage. On the spectrum of basic to applied science, the stories in this issue of Photonics Focus skew towards the pure science.
At the far end, we have a story that describes ongoing research into unfathomably short attosecond laser pulses that are yielding incredible new insights on electron behavior and control.
Moving slightly farther towards application, we have a story about laser propulsion, which presents a theoretically possible (but challenging to demonstrate) proposal to use lasers to propel spacecraft—very quickly—to Mars, or even into interstellar space.
And, finally, straddling that expectant moment right before an idea becomes an application, we have a story on optical power transmission, where scientists are working out how to convert electrical energy to light energy and back again, and thus deliver power to remote locations without the need for cumbersome cables.
Laser research has been racing forward since Ted Maiman opened the starting gate more than 60 years ago. As we look to the future, innovations in laser science promise to continue transforming our world in ways we can only begin to imagine.
Gwen Weerts, Editor-in-Chief
