Electromagnetic wavefront modulation apparatus

A light modification system comprising:

• a panel;
• a glazing unit comprising two or more thin sheets, wherein one side of a first outer sheet defines a first outer surface, and one side of a second outer sheet defines a second outer surface, the first outer surface being substantially parallel to the second outer surface, all of the sheets in the system substantially overlaying the first outer surface and positioned between the first and the second outer surface and oriented substantially parallel to the first outer surface, wherein the sheets comprise at least one static sheet and at least one moving sheet, including
• a first static sheet comprising a first high transmissivity set of regions, and at least one additional set of regions comprising a first low tranmissivity set of regions, and a first moving sheet comprising a second high transmissivity set of regions, and at least one additional set of regions comprising a second opaque set of regions,
• wherein the first and the second high transmissivity sets of regions are substantially transparent to light in the 400-700 nm range,
• wherein the first and the second low tranmissivity sets of regions are of substantially to low tranmissivity for light in the 400-700 nm range;
• and
• an actuation mechanism capable of translating at least the first moving sheet with respect to the first static sheet in at least one direction between at least a first position, in which the first high transmissivity set of regions are substantially aligned with the second high transmissivity set of regions such that there is a substantial overlap between them,
• wherein the overlap between the first high transmissivity set of regions and the second low tranmissivity set of regions is small or negligible,
• wherein the overlap between the second high transmissivity set of regions and the first low tranmissivity set of regions is small or negligible, and
• a second position, in which at least the second low tranmissivity set of regions significantly overlap the first high transmissivity set of regions, and in which at least the first low tranmissivity set of regions significantly overlap the second high transmissivity set of regions,
• wherein each region of the first and the second high transmissivity sets of regions is substantially or completely overlapped by a low tranmissivity region;
• wherein the sum of average sheet thickness over all of the sheets in the system does not exceed 0.8 mm,
• wherein at least one dimension of each region of the first and the second low tranmissivity sets of regions does not exceed 50 mm,
• wherein the combined weight of all of the sheets does not exceed 8 grams per 100 cm2 of area of coverage of the first outer surface,
• wherein the glazing unit is affixed onto the panel such that the first outer surface substantially abuts the panel and is substantially parallel to it, such that there is a significant transfer of sheet weight onto the panel wherein at least at vertical panel orientation at least the weight of the sheets is substantially or completely supported by the panel, and
• wherein in at least the first position the average separation between the panel and the second outer surface doesn't exceed 10 mm.