A newly developed near-infrared optical mammographer based on frequency-domain techniques was presented. In comparison with our former prototype with multiple sources and detectors, the new one used single source and detector. This structure not only eliminates the matching issues between the channels but also simplifies the system and reduces the cost. The results of intralipid and clinical experiments have proved that the system has high sensitivity and resolution, which indicates its promising potential to serve as a proficient method of breast cancer detection.