Lawrence J. Hogan, the Republican candidate for U.S. Senate in Maryland, made a clandestine campaign detour this week and flew to Texas for a series of last minute fund-raisers before next Tuesday's election.

The two private events this past Tuesday as well as mail contributions resulted in "the biggest single day of fund-raising" of his year-long campaign, according to campaign manager George Nesterczuk.

In all, Hogan, who has attacked his opponent, incumbent Sen. Paul S. Sarbanes (D), for receiving the bulk of his contributions from out of state, collected $30,000. Hogan made similar fund-raising swings to Texas and California last summer.

Hogan's campaign aides, concerned that negative press reports could hamper his progress in the closing days of the race, chose not to reveal his whereabouts until the Texas fund-raiser had been declared a success. They said earlier this week that Hogan was fatigued and that, on the advice of his doctor and his wife, was "taking a couple of days off" before a final campaign blitz.

The new surge of contributions from Texas and elsewhere -- amounting to about $150,000 during a two-week span -- will enable Hogan to run four new television advertisements statewide this week and over the weekend. His chances for victory now hinge almost entirely on the extent of his media effort, his aides said yesterday. They contend that each day of media exposure closes the gap between Hogan and Sarbanes by two or three percentage points. Newspaper polls taken during the last three weeks showed Hogan trailing Sarbanes by from 20 to 35 percent.

One 30-second television spot that will be aired until Friday features Democratic Lt. Gov. Samuel Bogley III, who was dropped from Gov. Harry Hughes reelection ticket, quoting former President Kennedy saying, "Sometimes party loyalty demands too much." The ad is designed to encourage Democrats, particularly blue-collar voters, to cross party lines and vote for Hogan.

The new ads represent a subtle new strategy. Until now, Hogan's media advisers have tried to transform his aggressive image into a positive feature. But that tactic was changed after a series of newspaper polls indicated Hogan's support is particularly weak among women, the state's largest voting bloc, who apparently have responded unfavorably to his aggressiveness.

Over the weekend and on Monday, Hogan will appear in a one-minute ad that emphasizes his family life and attempts to portray him as a more sensitive and thoughtful candidate.

Dwindling finances forced Hogan to curtail his media campaign for two weeks earlier this month. The campaign "really bogged down" after the newspaper polls and after the Washington Post reported that the White House would not provide full campaign resources to Hogan, Nesterczuk said. (Hogan's campaign recently asked the White House again to consider sending President Reagan to appear on his behalf in Maryland, but so far there has been no commitment). To help make up for the media lull, Hogan increased his personal campaign activities markedly and he became noticeably fatigued.

Last weekend, for example, Hogan arrived at a television debate in Baltimore four hours ahead of schedule and spent most of the afternoon napping in his campaign van while his opponent, Sarbanes, made several campaign stops.

"Are you tired, Larry?" a reporter asked Hogan after the debate.

"This will be the only honest thing I've said all evening," he joked. "Yes."