As I wrote this past weekend in my column, this year marks the 50th anniversary of the laser, a scientific innovation that has become commonplace in our everyday lives.
Combining scientific theory and brilliant engineering, it is one of the most innovative, fascinating, and commercially successful devices ever built. Lasers provide precise, selective and controlled high-power light beams for a variety of commercial and scientific uses.
In 1917 Albert Einstein (of course) first theorized the process that might make lasers possible. He called it “stimulated emission” (hence the “s” and the “e” in the laser acronym to go with “light amplification” and “radiation”), and his idea was harnessed in the first laser-like device (called a maser) built in 1959 by two Bell Laboratory scientists Charles Townes and Arthur Schawlow. Their device was actually a microwave device, not a visible one, but their theory and publications led to the construction of the first light laser in 1960.
I can’t imagine that Townes and Schawlow would have believed how useful and ubiquitous their device would become today.
In medicine, lasers are routinely used as cutting tools with the added benefit that their burning action seals and clots a cut immediately. For example, in laser eye surgery or even ulcer removal surgery, tissue can be removed without damaging surrounding areas.
In consumer electronics, lasers are used to read the surface of CDs or DVDs so that digital bits on the surface can be assembled into bytes of information and converted to continuous analog signals for our listening or viewing pleasure. Today’s high-speed printers use lasers to precisely map locations where toner particles should (or shouldn’t) stick to an imaging drum where they are subsequently fused into place.
The pure frequency output of a laser makes them ideal tools for use in sensitive chemical analysis applications, while the precision and narrow beams of lasers also make them ideal for distance measurements. During the Apollo 11 mission a laser was used to bounce a beam off an 18-inch reflector set up on the moon, measure the round trip travel time and determine (within a few meters) the precise distance to the Earth.
Semiconductor lasers combined with fiber optics provide for high-speed data transmission among computers. Downloading of movies and data can be over an order of magnitude or more faster than over copper wires. With the information and entertainment data explosion that has been going on for the past 20 years, fiber optic connections will continue to become more commonplace.
The controllability, speed and precision of lasers are quite an advantage in many applications. Industrial uses of lasers include cutting, blasting and welding. In the military and defense arena, powerful ones are successfully being used in tests to intercept and destroy ballistic missiles in flight.
We have come a long way since the development of lasers. Who knows what advancements applications lasers will bring in the next 50 years?
To me the more interesting question is: What will be the next innovation that will have comparable long-term impact? And has its theoretical groundwork already been laid, awaiting the next Townes and Schawlow to make it a reality?