Methods and devices for a display apparatus. In one aspect, a display apparatus includes a display device including a transparent layer, a display integrated circuit layer including one or more display control circuits, and a shielding layer between the transparent layer and the display integrated circuit layer, a near-infrared (NIR) light source and a visible light source, and a detector device including a detector integrated circuit layer including one or more detector control circuits, where a surface of the detector device contacts a surface of the display device, and a photodetector electrically coupled to at least one detector control circuit and including a detection region positioned to receive NIR light propagating from a front side of the display device to a back side of the display device along a path, where the shielding layer includes a filter region positioned in the path.