Olah faxed in his national letter of intent on Tuesday, officially making him a Wildcat after a complication prevented him from faxing the letter in November.
"I'm really excited," Olah said to PurpleWildcats.com on Monday. "I think and I know NU is the best place for me to be in. Academically and basketball-wise."
The addition of Olah helps sure up Northwestern's center position, which has seen its share of struggles during Carmody's tenure. Last season, 6-foot-8 forward John Shurna was forced to assume the role of center when Luka Mirkovic was inefficient.
Olah, a 7-foot, 275-pounder, will provide the big man that Northwestern has needed.
"With the addition of Alex, we add a powerful and talented big man to the team," said NU head coach Carmody in a statement. "Alex has a unique combination of size and skill and he has continued to improve in all aspects of his game."
Swopshire was seldom used on Louisville's Final Four team, playing in just over 13 minutes per game. The former four-star prospect was forced into a reserve role behind freshman Chane Behanan.
Swopshire joins Northwestern with one year of elibility -- after missing his 2010 season with a groin injury -- and the chance to be an impact player.
"It was a really great fit, a great situation," Teddy Swopshire, Jared's father, told PurpleWildcats.com. "Everything kind of lines up with what's (Jared)is looking for."
Swopshire, a native of St. Louis, brings high potential to Northwestern's frontcourt.
"We're excited to welcome Jared to the program," Carmody said. "He is a versatile player who brings Final Four experience to our roster. He has the ability to play multiple positions and will be an impact player on both ends of the court."
Sources also confirmed that Northwestern is still searching for prospects for its 2012 group.