We have explored double-layer-coated fiber optics using two-phase immiscible non-Newtonian fluid as a polymeric material. We have considered two layers, the first layer is assumed of soft material and the second consists of hard material. Resin flows are driven by fast-moving glass fiber and the pressurization at the coating die inlet. Two cases of temperature linearly varying at the boundaries have been discussed. The assumption of fully developed flow of non-Newtonian fluid permits an exact solution to the Navier–Stokes equations. The thickness of the secondary coating resin and the shear stress on the glass fiber, which are two basic output variables of practical concern, have been examined by several input parameters: two geometric parameters, i.e., radius of the glass fiber Rw and radius of the coating die Rd; two operational parameters, i.e., the velocity ratio U and power indices n1,2; the non-Newtonian parameter S1,2; and the nondimensional parameters H and ϕ. The comparison of the present work with published result predicts the close agreement.