The advancement of two-photon 3D lithographic techniques has enabled the production of sub-micron resolution optics with complex 3D geometries. This technology’s versatility enables the creation of intricate freeform optical components and diffractive optical elements within a miniaturized footprint. Furthermore, the capacity for rapid prototyping of these micro-optical components facilitates the realization of custom-tailored micro-optical systems for specialized applications. The purpose of this work is the development of a fiber-optic probe functionalized with a micro-optical assembly that enables quantitative spectroscopic analysis in the visible and near-infrared (VIS/NIR) regions. Employing a combination of optical design software and two-photon direct laser writing (TP-DLW) we demonstrate the functionalization of an optical fiber bundle for spectroscopic analysis. The methods used to produce this miniaturized optical system showcase a low-cost approach for realization of integrated micro-optical system that can facilitate the functionalization of chip-on-tip technology for applications from quality assurance in the food and drug industries, to spectral tissue sensing in medicine. Presented in this work is the progress toward optimizing the performance of the micro-optical components and the functionality of a prototyped micro-spectrophotometer at the tip of an optical fiber bundle, validated against a commercially available portable spectrophotometer.