Noe Yanez, 40, was charged in May 2012 on 6 counts of sex-related crimes.
During a preliminary hearing Friday, Yanez plead guilty to one count each of forcible rape, meeting a minor for lewd purposes, using a minor for sex acts, possession of child pornography, and two counts of false imprisonment by fraud or deceit.
He was sentenced to 11 years and eight months in state prison immediately following his guilty plea. Los Angeles Superior Court Judge Ronald S. Coen also ordered Yanez to register as a sex offender.
The former officer was fired by the Long Beach Police Department last June. The allegations involving five underage girls spanned from 2008 until shortly before he was charged in May 2012.
The Long Beach Police Department investigated the allegations.