Thomas, originally a second-round draft choice of the Washington Redskins in 2008 out of Michigan State, spent last season as a member of the Super Bowl champion New York Giants. Besides Washington and New York, Thomas was briefly in Carolina, where he played in just one game for the Panthers in 2010.
"When you put everything on the table from the different teams, Chicago was definitely a great fit for me as far as coming in and contributing right away at receiver, something I've been longing to do for awhile," Thomas said Thursday on "The Waddle & Silvy Show" on ESPN 1000. "I should have a great opportunity to do that."
The wideout has made his biggest impact in the NFL on special teams. He recovered two key fumbles for New York in last season's NFC Championship Game against the San Francisco 49ers.
"Special teams is something I feel like I can always contribute as, but I'm definitely here to be a receiver, and I'm looking forward to working with (quarterback) Jay (Cutler) and making things happen," he said.
Thomas has 43 career receptions for 482 yards and three touchdowns.
While at Michigan State, Thomas set a school record with 79 receptions as a junior before deciding to forgo his senior season for the NFL draft.
Thomas is the third receiver the Bears have acquired this offseason. The organization sent two third-round picks to Miami for Brandon Marshall, then signed wideout/kick returner Eric Weems at the onset of free agency.
At the very least, the Bears needed to fill two spots at wide receiver heading into this season. Sam Hurd was released last year after an arrest on drug-related charges, while Johnny Knox could face a long road to recovery after suffering a severe back injury late in the 2011 regular season.
Dane Sanzenbacher, who made the team last year as an undrafted rookie free agent, probably will have to compete with Thomas and others for a spot on this year's 53-man roster.