Abstract: The present invention is directed to an apparatus and method for coupling a coherent fiber-optic bundle to an electro-optical sensor. This invention provides accuracy and durability of coupling in operating conditions characterized by vibrations, shocks and fluctuating temperatures and pressures. It also reduces the reject rate previously experienced in such assembly work. The apparatus and method of the present invention employ a rigid guide plate for initiating and in most cases preserving transverse and angular alignment of the component bundle and sensor, and a transparent flexible cement to establish the correct proximity between the electro-optical sensor and the fiber-optic bundle and to achieve permanent mating of those two components. In certain applications the rigid guide plate can be dispensed with after assembly and curing of the cement.