Detectors (sensor) having detection capability ranging from visible to near-infrared region are very much required for multi-color image sensor, necessary for next generation bio-medical, bio-chem(ical), and security applications. The capability of using broadband detection in a single sensor would help to receive real-time imaging not detectable using today's CCD or CMOS sensor. We proposed a detector structure as a single sensor element (pixel) having the detection capability ranging from visible to 1.7 μm, wavelengths requiring in bio-chem, biomedical cell detection and security application. This invited paper has two-fold objectives: (a) provide a comprehensive overview of conventional photo detectors array (focal-plan array) and their types, being used in today's imaging, and (b) introduce a development of multi-color detector array (image sensor) which authors pioneered. The features of proposed multi-color detector are simple structure, low-cost, high quantum efficiency, high sensitivity, and high speed. Performance results so far attained will be presented along with its possible applications.