The disclosure relates to an optical system for an augmented reality apparatus, comprising: an image source; and a polarizing beam splitter. The polarizing beam splitter has a beam splitting side adjacent to the image source and a transmission side facing away from the image source. The polarizing beam splitter is arranged such that light emitted from the image source is able to be non-perpendicularly incident on the beam splitting side and be at least partially reflected. The polarizing beam splitter is configured such that when light is incident on the beam splitting side, a polarized light component, whose polarization is in a first direction, passes through the polarizing beam splitter and is transmitted through the transmission side thereof, and a polarized light component, whose polarization is in a second direction perpendicular to the first direction, is reflected from the beam splitting side. The optical system also comprises a polarizer disposed between the image source and the beam splitting side of the polarizing beam splitter, and the polarizer is configured to allow polarized light, whose polarization is in the second direction, to be transmitted therethrough and polarized light, whose polarization is in the first direction to be absorbed.