Cheered by success at the grass-roots level in the November elections, Maryland Republican officials are turning their eyes to the U.S. Senate seat held by Democrat Barbara A. Mikulski and interviewing some GOP notables they want to solicit for the campaign.

Names being raised range from that of former U.S. attorney Joseph E. diGenova, who says he's only listening at this point, to corporate heads and a literary celebrity. None has yet taken formal steps such as establishing exploratory committees, according to state GOP Chairman Joyce Lyons Terhes.

But after the Republicans captured three suburban county executive seats, one congressional office and several slots in the state General Assembly, Terhes said morale and interest are running high on the subject of 1992, when Mikulski's term ends. Mikulski was a popular Baltimore representative for a decade before moving up to the Senate in 1986.

"Two years ago, four years ago, when we wanted candidates we almost had to get on our hands and knees," Terhes said. "But when you see what was done on Election Day, and the dramatic turnaround . . . there is interest there."

Republican activists have already talked to diGenova, the former U.S. attorney in the District whose prosecution of corruption in the Barry administration made him a well-known figure in the area. Terhes said diGenova was "high on my list" of people to call next year.

DiGenova said yesterday he had agreed to meet with a group of people urging him to run, but added it was unlikely he would leave his private law practice for a political campaign. "I have had people come and approach me but I doubt very much that anything will come of it," he said.

Others mentioned for the race include Alan Keyes, the United Nations official who ran against U.S. Sen. Paul S. Sarbanes in 1988; Joshua Smith, chief executive officer of Montgomery County's Maxima Corp., the area's largest black-owned company; and suspense novelist Tom Clancy, who was approached about a congressional race this year but declined.

The roster follows the state GOP's recent strategy of tapping federal officials who live in the Maryland suburbs for high-profile races. So far the strategy hasn't worked: Sarbanes easily beat Keyes; Mikulski easily defeated Linda Chavez, former staff director for the U.S. Commission on Civil Rights; and Gov. William Donald Schaefer beat retired diplomat William S. Shepard of Potomac.