1. An imaging device to sense patterns of incident light over a wavelength band of interest, the imaging device comprising: a photodetector array defining a focal plane; and a phase grating defining a transverse plane to receive the incident light, the phase grating including: a pair of adjacent first grating segments, of a first segment width W 1 , defining a boundary of odd symmetry extending in the transverse plane, the first grating segments inducing destructive interference below the boundary of odd symmetry and at the focal plane for the incident light within the wavelength band of interest; a pair of second grating segments, one on either side of the pair of first grating segments, of a second segment width W 2 greater than the first segment width, the second grating segments inducing destructive interference below the boundary of odd symmetry and at the focal plane for the incident light within the wavelength band of interest; and a pair of third grating segments, one on either side of the pair of second grating segments, of a third segment width W 3 , the third grating segments inducing destructive interference below the boundary of odd symmetry and at the focal plane for the incident light within the wavelength band of interest.