Maryland Republican Lawrence J. Hogan has temporarily stopped his crucial television advertising campaign because he collected only $100,000, far short of his goal, during the critical month of September.

Hogan campaign manager George Nesterczuk said "contributions dried up for two weeks" after the Washington Post reported that top GOP strategists and the White House viewed Hogan's campaign as "a long shot" at best. Soon after, a poll by the influential Baltimore Sun showed Sarbanes leading Hogan 59 percent to 25 percent. Both reports hurt fundraising efforts and this, in turn, resulted in "two weeks lost in media time," according to Nesterczuk.

Campaign finance reports filed yesterday showed that Hogan has raised about $400,000 since announcing for office a year ago, about one-third of the $1.2 million amassed by incumbent Democrat Paul S. Sarbanes.

However, in the past two weeks, money has begun to flow to Hogan, with contributions of between $70,000 and $80,000 coming in, Nesterczuk said. He anticipates raising another $150,000 in the next two weeks. Those funds, plus another $35,000 from the National Republican Senatorial Committee -- which has already given him $200,000 -- would allow Hogan to mount a media blitz in the campaign's closing days, Nesterczuk said.

Sarbanes has stayed far ahead in the fundraising race since the campaign began. The senator's fundraising stock was given a boost among liberal groups around the country last year when the National Conservative Political Action Committee (NCPAC) made him its number one target for defeat in 1982. Since then the right-wing group has spent about $625,000 to defeat Maryland's junior senator. Meanwhile, the normally low-key Sarbanes has traveled the country, picking up thousands of dollars at receptions in New York City, Chicago, San Francisco, Los Angeles and Detroit.

For instance, in September, Sarbanes and Sen. Quentin Burdick (D-N.D.), another of NCPAC's targets, attended an anti-NCPAC fundraiser in New York City from which Sarbanes collected about $12,000. Political action committees run by labor unions and liberal groups have also been generous. Labor alone has contributed more than $200,000 to his campaign, according to reports filed with the Federal Election Commission.

Hogan's attempt to tap into the conservative movement's money has proved less successful. A trip to Los Angeles to woo wealthy conservatives last month appears to have resulted in only about $1,100 in contributions, according to the FEC report filed yesterday.

Hogan has two major fundraisers planned this month, one of them hosted by Washington developer Oliver T. Carr. Meanwhile, Hogan, his wife Ilona and top campaign aides are busy calling potential contributors and Hogan has sent out a direct-mail solicitation letter to more than 15,000 people, according to Nesterczuk.

Several Maryland Republicans said last month that the flow of contributions in late September and early October would be crucial to Hogan's Senate quest. "If they don't raise the money in the next three weeks," said one Republican on Capitol Hill, "they can kiss it goodby."

But Nesterczuk said yesterday: "The degree of media blitzing we can do will depend on how much we can raise in the next two weeks. That's when the story will be told."

Other reports filed with the FEC yesterday showed that incumbent Rep. Michael D. Barnes has raised $143,317 in his bid for a third term in Maryland's eighth congressional district. His Republican challenger, former school board member Elizabeth W. Spencer, has raised only $4,715.

Barnes' report shows he raised more than $39,000 during the last two months, with $25,000 from individual contributors and $13,000 from political committees.

Barnes spent $126,706 as of Sept. 30, and had $58,414 left for the final weeks, and no debts.

Spencer's campaign reported it has $2,230 left. Her campaign has spent $15,484 so far. Spencer managed to collect only $1,850 during the last two months. Her campaign has been kept financially afloat by a $13,000 loan she made to her own campaign.