Metallic copper is easily thermally doped into certain chalcogenide glasses during vacuum evaporation on the glasses. The doped Cu causes a change in the optical absorption of the glass. A stable photosensor could be successfully made by providing a thin Ag layer between Cu and chalcogenide layer on the polyester film base. When the sensor was exposed to light, metallic Ag was photodoped into the glass. After that, Cu layer was possible to be thermally doped into the glasses at the photodoped area. The photo-doping process depended greatly on the composition of the chalcogenide glass. The modification of As-S glass with small amount of Te or Se was effective to improve the photo and thermal doping. When a sensor consisting of Cu-Ag-(As₂S₈) ₁Te_0.4 or Cu-Ag-(As₂S₈) ₁Se_0.4 was heat processed after exposing to light (20mJ/cm²), the thermal doping of Cu into the glass could be enhanced. As the results, it was found that the D -log E curve was shifted parallel to less exposure energy side.