A display device includes a light source, a spatial light modulator (SLM), and an optical assembly that includes a first reflective surface and a second reflective surface that is opposite to the first reflective surface. The light source is configured to provide illumination light. The optical assembly is configured to receive the illumination light. At least a first portion of the illumination light received by the optical assembly is transmitted through the first reflective surface toward the second reflective surface, is reflected by the second reflective surface toward the first reflective surface, is reflected by the first reflective surface toward the second reflective surface, and is transmitted through the second reflective surface. The SLM is configured to receive and modulate the portion of the illumination light transmitted through the optical assembly, and to output the modulated light. A method performed by the display device is also disclosed.