Texas Instruments has developed a Phase Light Modulator (PLM) based on Digital Light Processing (DLP) System, which alters the distribution of the light field. This paper explores the fundamental diffraction properties of PLM using the blazed grating model, investigates its capability to steer beams and tests its uniformity as a light field modulator. We selected a typical light field distribution to test the contrast ratio and examined how changing the light field distribution through PLM affects contrast ratio. When there is a single spot area exists in the modulated light field, decreasing the proportion of the individual spot to the entire image area, increases the contrast ratio; When there are multiple spots in the modulated image, increasing their number, decreases the contrast ratio. The feasibility of arbitrarily manipulating light field illumination for display system applications is verified by combining PLM with Digital Micromirror Device (DMD), leading to improved contrast ratios and better realization of High Dynamic Range (HDR) in projected images.
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