Projection optics for optical computing

An optical computing element comprising:

• first, second, and third lens arrangements along an optical axis;
• a two-dimensional modulator array comprising multiple sets of modulator elements, the modulator elements within each set being arrayed along a first direction, and the multiple sets being arrayed along a second direction, the first and second directions being mutually orthogonal directions in a modulator plane perpendicular to the optical axis;
• and
• a source array comprising light sources arrayed, in a source plane orthogonal to the optical axis, along the second direction,
• wherein the first and third lens arrangements are rotationally symmetric about the optical axis,
• wherein the second lens arrangement is positioned between the first and third lens arrangements and has an optical power of a first magnitude in the first direction and an optical power of a second magnitude in the second direction,
• wherein the first, second, and third lens arrangements are configured to create an image of the light sources on the modulator array that is focused in the second direction and out of focus in the first direction such that light from different ones of the light sources is spread along the first direction over different corresponding sets of modulator elements.