They were five of America's 1981 Nobel laureates in science, back again on Swedish soil. And though they may have left their medals at home last night, the curiosity that won them was as active as ever.

"I'm concerned about attempts to throttle communication between international scientists in the name of security," said Arthur Schawlow of Stanford, who shares the Nobel prize in physics with Nicolaas Bloembergen of Harvard.

It was only half of the concern Schawlow and others brought to Washington for their appearances before the House Committee on Science and Technology today. The other half was money.

"That's how science is translated--it's always a matter of money," said Bloembergen.

Taking advantage of the timing, Swedish Ambassador Wilhelm Wachtmeister and his wife, Ulla, entertained them all at a reception in the Swedish Embassy. Many among Washington's scientific community turned out for it; and while the decibel level was on a par with most parties here, the conversational level was high-tech with words and phrases like laser, spectroscopy, and strabismus.

Schawlow said he hasn't been able to find out who is behind a growing restriction on American scientists and the flow of information to their foreign colleagues. But he said it started in the late days of the Carter administration and it seemed "sort of a revival of what happened in the 1950s when the Office of Strategic Information prevented nonclassified information from reaching foreigners."

Bloembergen said he thought it was happening not so much in science as in the exchange of technical information. But he also felt that if the government is concerned about it then they should classify that information.

Roald Hoffmann of Cornell University, who shared last year's chemistry prize with Japanese scientist Kenichi Fukui, voiced dismay over the breaking of exchanges with the Soviet Union.

"One way or another the exchanges have been decimated," he said. "It's important for us that we have people who know what's going on there. Someone has got to keep talking while governments aren't friendly, and scientists have that opening."

Against a background of brightly colored contemporary paintings, the works of Countess Wachmeister, the guests paused in their dialogues to sample marinated raw salmon and tiny Swedish meatballs.

Towering above everyone was another Nobel laureate, Dr. Glenn T. Seaborg, formerly chairman of the Atomic Energy Commission; among the crowd were former senator John Sherman Cooper, columnist Marquis Childs and Rep. Larry Winn (R-Kan.).

Threading their way among them were the Nobel prize winners, back together again as they were nearly three months ago in Stockholm.

There were some reminiscences.

"When you're a Nobel prize winner in science the students at the University there induct you into the Order of the Ever Smiling Jumping Frog," Schawlow told David H. Hubel of Harvard, who shared with Torsten N. Wiesel half of last year's prize in medicine. Their work has been important in treating strabismus, or crossed eyes, in the young. "They put a ribbon around our heads. They made us jump around the stage like frogs."

"There wasn't anything like that for us in medicine," said Hubel, laughing.

Wiesel told what he plans to tell the House committee today: "The basic science establishment in this country is a national resource and if it is not given proper support, it probably will die."

Wiesel, who with Hubel received $90,000 for "breakthrough" discoveries of the way the brain processes visual images, said the effect of not training people now will take its toll in 10 to 20 years.

"Of all the research grants being approved, only 15 percent are being funded," he said. "You tell a young person that, and he will go into other careers. It's a crisis not fully appreciated."

He said the National Institutes of Health did a study in 1980 and found that for every $1 invested in the support of science there is a return of $100.

"It's a very good investment."

Stanford physicist Schawlow, one of the inventors of the laser, said the number of physicists being produced has dropped dramatically, and he is afraid that we're heading down to pre-Sputnik levels.

Winning the other half of the medicine prize was Roger W. Sperry, of California Institute of Technology, who wasn't there last night.

The team of Bloembergen and Schawlow shared half the $180,000 physics prize for work in developing laser techniques to sort out the atomic properties of substances, something called laser spectroscopy.

Of the significance of the Nobel, Wachtmeister was proud. "We think this has stood the test of time."