A fiber optic collimator system, a fiber optic collimator array, and a fiber optic collimator array system, which can reduce difficulty in an alignment process, minimize a coupling loss, and prevent the optical characteristics from deteriorating. An optical fiber is fused to one end of a GRIN lens made of quartz glass containing one or more selected from Sb2O3, Ta2O5, TiO2 and ZrO2 as a refractive index regulating substance, to form an optical fiber with a GRIN lens. Since an adhesive is not used, the core alignment of the GRIN lens and the optical fiber can be facilitated by a self alignment effect without deteriorating the optical characteristics. Moreover, the coupling loss is remarkably reduced by appropriately setting a refractive index distribution constant g of the GRIN lens. By fabricating the fiber optic collimator system, the fiber optic collimator array, the fiber optic collimator array system using the optical fiber with a GRIN lens can reduce the difficulty in the core alignment process, minimize the coupling loss, and prevent the optical characteristics from deteriorating.