The 27-year-old midfielder will leave VfR Aalen on a free transfer and has agreed terms on an initial contract through to 30 June 2015, valid for both the Bundesliga and Bundesliga 2 and including performance-related options to extend.
Dausch joined Aalen from VfB Stuttgart's U-23 in the summer of 2009. He helped the Regional League outfit earn promotion to Division 3 in his first season there and, last year, to Bundesliga 2. He has made 20 appearances in all competitions for VfR so far this season, scoring eight goals.
"Martin Dausch is a very durable player with an eye for goal, who can be deployed in a variety of attacking midfield roles. He's doing well with Aalen in his first Bundesliga 2 season and certainly has the potential to develop even further," Union coach Uwe Neuhaus said.