The 26-year-old will bolster a Schalke defence weakened for the start of next season by the absence of Japan’s Atsuto Uchida, who underwent a knee operation earlier this month.
Caicara won three league titles in Bulgaria and also featured for Ludogorets in last season???s Champions League, and coach Horst Heldt has tipped him to succeed in the Bundesliga.
“We saw last season how important it is to have two players for each position if possible,” Heldt told the club’s official website.
“With Junior Caicara, we now have another skilled right-back in the team together with Atsuto Uchida, who will certainly continue to help us.
“We’ve watched him intensely over the past months and are convinced by his ability.
“Junior is massively looking forward to the new tasks, really wants to take the next step forward in his career and break through at Schalke.”