High count optical fiber cable having encased fiber ribbon stack

Embodiments of the invention include an optical fiber cable (10) having improved optical fiber densities and no central strength member. The optical fiber cable includes one or more multi-fiber unit tubes (16) having an optical fiber ribbon stack (12) snugly positioned therein. The diagonal length of the ribbon stack is approximately equal or, alternatively, at least 90% of the inner diameter of the unit tube. The multi-fiber unit tube is made of low-density polyethylene (LDPE) or other material soft and flexible enough to allow the ribbon stack to be relatively firmly positioned therein without affecting the optical fiber performance. The optical fiber cable includes one or more filling materials (14) such as yarn fillers positioned, for example, between the ribbon stack and the inner walls of the unit tube, to maintain the shape of the multi-fiber unit tube. The yarn filler material includes super absorbent polymers to reduce propagation of water down the unit tube.