Jason Alan Marian, 32, was convicted of secretly videotaping five teenage girls in his bathroom during a pool party at his home and of sexually assaulting a 16-year-old girl on another occasion in the same house.
Marian taught dance at the Mission Viejo Dance and Performing Arts Center.
The judge also ordered Marian to register as a sex offender.
In a separate proceeding, Marian faces trial for two more sexual assault charges involving the same 16-year-old girl.