By Patricia Daukantas
Charles Hard Townes—Berkeley professor, Nobel laureate in 1964, OSA Honorary Member since 1970—probably needed no introduction to the attendees at yesterday’s LaserFest History Symposium at CLEO/QELS. But moderator Joseph Giordmaine still gave him a kind introduction, and Townes in turn paid a gracious tribute to Ted Maiman on the 50th anniversary of his ruby laser. Then Townes delivered some personal anecdotes about his own lengthy career—some of which you may not already have heard.
Albert Einstein first described stimulated emission in 1917, and the phenomenon occurs in outer space, Townes pointed out. “If we had looked carefully, we could have discovered them there,” he added. Instead, the ideas for masers and lasers pretty much lay dormant for a few decades. “How blind we are to new ones,” he said.
Townes said that his radar engineering work during World War II turned out to be important to his scientific career, because in dealing with radar interference from water vapor in the atmosphere, his studies led to the start of microwave spectroscopy.
After telling the famous story of how he got a crucial insight while sitting on a park bench, Townes recalled how he was delivering a lecture when Jim Gordon rushed in the room to shout about their maser, “It’s working!” Professor and students all rushed out of the classroom to see what was happening in the lab.
Also, while Townes was on sabbatical leave in the 1950s, he visited Tokyo, where he talked to a biologist who was studying population fluctuations among single-cell organisms. “That’s just what I was working out for the laser,” Townes said. “I just had to add one term.” This talk with the mathematical biologist gave him critical insight into managing energy-level populations.
Townes’ brother-in-law, Arthur Schawlow, was the one who came up with the idea of two parallel plates because he had been working with Fabry-Pérot interferometers. In 1958, they asked Schawlow’s employer, Bell Labs, to patent their ideas … but the telephone company’s research laboratory refused to file an application “because light had never been used for communications.” So Schawlow and Townes went ahead with the publication of their famous theoretical “optical maser” paper in the Physical Review.
The next two LaserFest History Symposium speakers, C. Kumar N. Patel and Marshall Nathan, highlighted two main branches of laser research since the days of Ted Maiman: high-power gas lasers and the ubiquitous semiconductor lasers. Patel, who invented the carbon dioxide laser at Bell Labs, now develops applications for quantum cascade lasers through his own company, Pranalytica Inc. of Santa Monica, Calif. (U.S.A.). Nathan, who worked for IBM and then joined the University of Minnesota (U.S.A.), said that the development of semiconductor lasers in the 1960s was due to a lot of hard work and not much serendipity.
At the end of the symposium, the subject “zoomed out” from tiny lasers to the biggest lasers in the world—namely, the 192 gigantic beam lines of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, just a few miles from the conference site in San Jose, Calif.
“I was 10 years old when the laser was invented, and it was the perfect time to be born,” said NIF director Edward Moses. As soon as he saw his first helium-neon laser in 1968, he knew that he wanted to make laser physics his life’s work.
John Nuckolls -- a Livermore physicist who is still with the lab after 55 years—proposed to use lasers for fusion energy as soon as Maiman’s working laser was announced in 1960, Moses said. He remains optimistic that NIF will achieve ignition in the next couple of years, develop a prototype inertial fusion energy plant by 2020, and see the technology go commercial by 2030. “It sounds fast, but look at the laser,” he added.
As I said in the previous blog post, the historical symposium drew a large crowd, especially considering that it was the first CLEO event other than the short courses. Among the audience I saw at least five other OSA Past Presidents besides Tony Siegman, plus numerous other OSA volunteers and Fellows. During the coffee break I ran into OSA Honorary Member John L. “Jan” Hall, another one of our Nobel laureates for laser-related work. He told me that he was really enjoying the proceedings.
What would a birthday be without a party? Following the symposium, LaserFest held a reception at which attendees could mingle with the distinguished speakers, and we were offered the most adorable LaserFest cupcakes!
CLEO/QELS and CLEO:Applications continuing today with a full day of technical sessions, followed by the first of two plenary sessions this evening. In addition to this OPN blog, you can follow the action on CLEO’s social media page. Enjoy!
2010-05 May, CLEO/QELS, Lasers, Lasers, CLEO