A multi-channel fiber optic rotary joint mechanism has been invented in which optic signals can be transmitted simultaneously from a rotating fiber optic collimator bundle and a stationary fiber optic collimator bundle through an opto-mechanical de-rotating mechanism, which includes an optic de-rotating element, an internal gear and an flexure anti-backlash mechanism. The optic de-rotating element, is positioned in the path between said rotating fiber optic collimator bundle and said stationary fiber optic collimator bundle. The internal gear mechanism provides 2:1 speed ratio for the rotating fiber optic collimator bundle and the optic de-rotating element.