An ultra-compact projector module comprising: a plurality of illuminators , each of which emits a beam of a different spectrum of light directed towards a reflective prism , the plurality of illuminators being positioned relative to each other with a predetermined pitch distance so that the beams of different spectrums of light emitted from the plurality illuminators geometrically overlap prior to being detected by a plurality of photodetectors ; the reflective prism , positioned in-between the plurality of illuminators and the plurality of photodetectors , the reflective prism being configured to direct some of the incident light of the beams towards the plurality of photodetectors ; the plurality of photodetectors , including a different photodetector for each illuminator in the plurality of illuminators , wherein each photodetector is associated with a corresponding color filter such that the ultra-compact projector module includes a plurality of color filters ; and the plurality of color filters , including a different color filter for each photodetector in the plurality of photodetectors , each color filter being positioned in-between the reflective prims and a corresponding photodetector proximately to the corresponding photodetector and in-between the corresponding photodetector and a corresponding illuminator , wherein each color filter included among the plurality of color filters passes a corresponding spectrum of light while filtering out other spectrums of light and such that each photodetector included among the plurality of photodetectors receives spectrally filtered light having passed through one of the plurality of color filters , each color filter having a surface area that is larger than a surface area of the proximally positioned and corresponding photodetector . a plurality of illuminators , each of which emits a beam of a different spectrum of light directed towards a reflective prism , the plurality of illuminators being positioned relative to each other with a predetermined pitch distance so that the beams of different spectrums of light emitted from the plurality illuminators geometrically overlap prior to being detected by a plurality of photodetectors ; the reflective prism , positioned in-between the plurality of illuminators and the plurality of photodetectors , the reflective prism being configured to direct some of the incident light of the beams towards the plurality of photodetectors ; the plurality of photodetectors , including a different photodetector for each illuminator in the plurality of illuminators , wherein each photodetector is associated with a corresponding color filter such that the ultra-compact projector module includes a plurality of color filters ; and the plurality of color filters , including a different color filter for each photodetector in the plurality of photodetectors , each color filter being positioned in-between the reflective prims and a corresponding photodetector proximately to the corresponding photodetector and in-between the corresponding photodetector and a corresponding illuminator , wherein each color filter included among the plurality of color filters passes a corresponding spectrum of light while filtering out other spectrums of light and such that each photodetector included among the plurality of photodetectors receives spectrally filtered light having passed through one of the plurality of color filters , each color filter having a surface area that is larger than a surface area of the proximally positioned and corresponding photodetector . <EOS>