A diamond probe is suitable to be attached to an Atomic Force Microscope and is created with a tip that incorporates a one or more Nitrogen Vacancy (NV) centers located near the end of the tip. The probe arm acts as an optical waveguide to propagate the emission from the NV center with high efficiency and a beveled end directs excitation light to the NV center and directs photoluminescence light emanating from the NV center into the probe arm. The probe tip is scanned over an area of a sample with an electric charge, such as a field effect transistor or flash memory. Optically Detected Spin Resonance (ODMR) is measured as the probe tip is scanned over the area of the sample, from which a characteristic of the area of the sample with the electric charge may be determined.