Gordon Gould, 85, a physicist who spent decades trying to prove he invented the laser while in graduate school and who eventually received several key patents for laser technology, died Sept. 16 at Lenox Hill Hospital in New York City. He had circulatory and vascular ailments.

Mr. Gould is credited with coining the term laser, which stood for "Light Amplification by Stimulated Emission of Radiation."

Lasers amplify light waves of atoms that have been stimulated to radiate and concentrates them in a very narrow and intense beam. They have become an essential part of daily living, used in such devices as bar-code readers and CD players. Lasers have much wider applicability than an earlier technology of amplified microwaves, called masers, which inspired Mr. Gould's thinking.

While studying physics at Columbia University, Mr. Gould said, he conceived the idea for the laser Nov. 9, 1957, in the middle of the night. After jumping from bed, he chain-smoked his way through the weekend and that Wednesday raced his notebook from his Bronx, N.Y., apartment to a candy store to have it stamped by a notary public.

Confused by a lawyer's advice, he thought he first needed a working model and neglected to apply for a patent. This was a costly oversight, allowing other scientists to win credit for the laser, which Mr. Gould believed could cut, weld, measure distances and create heat that would trigger nuclear fission.

He left school to create a laser model for a defense contractor. But his youthful participation in a Marxist study group in Greenwich Village left him without the required clearances to work on the top-secret project he had initiated.

This delayed his quest and triggered the decades-long legal fight for wider recognition.

Richard Gordon Gould was born in Manhattan on July 17, 1920. His father was an editor at Scholastic magazine, but it was his mechanically gifted mother who encouraged his interest in such inventors as Thomas Edison. She bought him his first Erector Set of toy buildings.

Mr. Gould was a 1941 physics graduate of Union College in Schenectady, N.Y., and received a master's degree in physics from Yale University in 1943.

He spent time working in New York on the Manhattan Project, the Allied wartime effort to create an atomic bomb, but his security clearance was revoked because of his and his first wife's involvement with the Marxist study group.

"With the takeover in Czechoslovakia in 1948, I suddenly had the blinders removed from my eyes," he later said. "My wife didn't, and we parted company soon after."

A teaching stint at City College of New York in the early 1950s ended during a politically motivated purge of communist sympathizers in academia. He refused to testify against colleagues, but future Nobel laureate Polykarp Kusch, his adviser at Columbia, found him a research position in the radiation lab.

He worked there closely with physicist Charles H. Townes, a future Nobel laureate who became Mr. Gould's rival for credit on the laser patent. Townes was renowned for his work on the maser, and he would eventually team with his brother-in-law, Arthur Schawlow, a physicist at Bell Telephone Laboratories, on what they called the "optical maser."

This was essentially the laser, as Mr. Gould called it in his notebook. Mr. Gould's late-night "eureka" moment and run to the candy store prompted him to leave Columbia in 1958 and begin a desperate attempt to build a working model.

His work, on a $1 million contract for New York-based defense researcher Technical Research Group Inc., was slowed by his security problems. And his patent, filed in 1959, underwent years of review because of competing claims.

Townes and Schawlow received their patent for an optical maser in 1960. That same year, Theodore H. Maiman of Hughes Research Laboratories built the first working laser.

Although Technical Research Group financed Mr. Gould's initial legal struggle, he eventually bought back the rights to his patents. After several setbacks, his chief advocate became Richard I. Samuel, a New Jersey patent lawyer. Samuel focused on a U.S. Patent and Trademark Office ruling from the early 1970s that Mr. Gould's patent application included several inventions, not just one.

In 1977, the patent office approved Mr. Gould's first commercial patent, for an optically pumped laser used in surgeries and for such industrial purposes as cutting and welding.

Big businesses that depended on laser technology and might have owed royalties to Mr. Gould began legal challenges. Attorneys for General Motors even argued that Greek mathematician Archimedes's reputed use of a lens to set a Roman ship on fire demonstrated the idea that lasers were far from new.

After a tortuous legal proceeding, U.S. District Judge Thomas A. Flannery ruled in 1985 that the patent office had made errors in denying Mr. Gould's patent application for the gas discharge laser, another device used in industry and medicine.

Flannery's ruling helped defeat the remaining lawsuits. By the late 1980s, Patlex, the company Mr. Gould helped form to litigate and license patents, began reaping millions of dollars from more than 200 companies.

He was inducted into the National Inventors Hall of Fame in 1991.

All told, the rulings netted Mr. Gould tens of millions of dollars, far more than the reported $6 million spent in his defense over the years. His last laser patent expired this year.

Mr. Gould said he rarely was alarmed by wins and losses in the courtroom, generally swatting away unfavorable developments as "annoying." He was busy with other lucrative enterprises, including a Montgomery County-based optical communications company, Optelecom Inc., from which he retired in 1985.

His interests included sailing, and at one time he owned a boat called the Wonny Larue, named after an ancestor he claimed was a pirate. He chose the name in part because he felt no one would steal it.

His marriages to Glen Gould and Ruth Gould ended in divorce.

Survivors include his wife, Marilyn Appel of Sag Harbor, N.Y.

Gordon Gould was awarded a patent for the gas discharge laser in 1987, ending a 30-year legal battle.