Thermally induced stresses in an optical glass fiber epoxy bonded into a thin-walled elliptical metal enclosure are analyzed. The emphasis is on the fiber microbending and possible buckling. The adverse effect of voids in the epoxy on the stresses in the fiber and in the epoxy itself is also addressed. The developed analytical models are easy-to-use, and clearly indicate the role of various geometrical and materials factors affecting the fiber propensity to buckling and its delamination from the epoxy. The obtained results can be used in the analysis and design of optical fiber structures epoxy bonded into elliptical enclosures.