A projection system, comprising: a first laser light source comprising a left-eye set of lasers configured to emit a first-eye light, wherein the first-eye light includes a first set of wavelengths; a second laser light source comprising a right-eye set of lasers configured to emit a second-eye light, wherein the second-eye light includes a second set of wavelengths; a first projector including first projection optics configured to receive a first input light; a second projector including second projection optics configured to receive a second input light; and an optical switch configured to be switched between a first mode and a second mode, wherein the optical switch is configured to, in the first mode, combine the first-eye light and the second-eye light into a combined light and direct the combined light to the first projection optics as the first input light, wherein the first and the second set of wavelengths consist respectively of three primary wavelengths, wherein the combination of the respective three primary wavelengths provides six primary wavelengths; wherein the first mode is a 2D mode, in which the combined light is projected by the first projection optics to generate a six-primary 2D image, and wherein all light from both left-and right-eye sets of lasers are switched into one projector in the 2D mode, and wherein the second mode is a 3D mode, wherein the optical switch is configured to direct the three primaries emitted by the first laser light source to the second projection optics and to direct the three primaries emitted by the second laser light source to the first projection optics to generate a three-primary left-eye image and a three primary right-eye image. a first laser light source comprising a left-eye set of lasers configured to emit a first-eye light, wherein the first-eye light includes a first set of wavelengths; a second laser light source comprising a right-eye set of lasers configured to emit a second-eye light, wherein the second-eye light includes a second set of wavelengths; a first projector including first projection optics configured to receive a first input light; a second projector including second projection optics configured to receive a second input light; and an optical switch configured to be switched between a first mode and a second mode, wherein the optical switch is configured to, in the first mode, combine the first-eye light and the second-eye light into a combined light and direct the combined light to the first projection optics as the first input light, wherein the first and the second set of wavelengths consist respectively of three primary wavelengths, wherein the combination of the respective three primary wavelengths provides six primary wavelengths; wherein the first mode is a 2D mode, in which the combined light is projected by the first projection optics to generate a six-primary 2D image, and wherein all light from both left-and right-eye sets of lasers are switched into one projector in the 2D mode, and wherein the second mode is a 3D mode, wherein the optical switch is configured to direct the three primaries emitted by the first laser light source to the second projection optics and to direct the three primaries emitted by the second laser light source to the first projection optics to generate a three-primary left-eye image and a three primary right-eye image.