Method of calibrating a holographic projector

A system comprising a holographic projection system, the holographic projection system comprising:

• a light source arranged to output light;
• a display device arranged to display a diffractive pattern comprising a hologram of a target image and to receive light from the light source and output spatially modulated light in accordance with the diffractive pattern to form a holographic reconstruction of the target image at a replay plane;
• a mask arranged to block at least a portion of the holographic reconstruction;
• a camera arranged to capture an image of a portion of the holographic reconstruction that is visible downstream of the mask;
• and
• a processor arranged to:
• display a primary diffractive pattern on the display device;
• the primary diffractive pattern comprising a first hologram of a first target image comprising a picture area and a non-picture area and a phase-ramp function arranged to translate the holographic reconstruction;
• and
• capture an image of the holographic reconstruction to measure a property of a boundary between the picture area and the non-picture area;
• wherein the mask is arranged to block the non-picture area in an absence of the phase-ramp function.

Tangible, non-transitory computer-readable media comprising program instructions therein, wherein the program instructions, when executed by one or more processors, cause a system to perform a method of calibrating a holographic projector comprising:

• displaying a primary diffractive pattern on a display device, wherein the primary diffractive pattern comprises a first hologram of a first target image and a phase-ramp function;
• illuminating the primary diffractive pattern to form a first holographic reconstruction of the first target image on a replay plane, wherein the first target image comprises a picture area and a non-picture area, and wherein the phase-ramp function is arranged to translate the first holographic reconstruction;
• blocking at least a portion of the first holographic reconstruction using a mask, wherein the mask is arranged to block the non-picture area in an absence of the phase-ramp function;
• and
• measuring a property of a boundary between the picture area and the non-picture area.