A handheld electronic device (100), e.g., cellular telephone handset, is provided with a color laser projector system (300) that includes an optics module (112) includes a large green laser module (316) and smaller red (314) and blue (318) laser modules in a compact arrangement in which the red (314) and blue (318) laser module are arrange within a dimensional extent D1 of the green laser module (316) in a direction that is perpendicular to a direction in which a green laser beam (426) is emitted. The optics module (112) uses a single photo-detector 328 to sense the intensity of laser beams emitted by the three laser modules (314, 316, 318). A prism can be used to direct light to a bare chip (804) photo-detector (328). Alternatively, a right angle mounted surface mount photo-detector (328) can be used.