A pixelated, wire-grid diffraction grating is designed, fabricated, aligned, and mounted on an active focal plane array of a camera operating in the visible. The resulting design of the pixelated wire-grid polarizer array eschewed the need for fine translational alignments and drastically reduced cross-talk between pixels detecting differing polarization states. Using common optomechanical elements in conjunction with a novel correlation-based alignment metric, we are able to achieve repeatable angular alignments to better than 0.004 deg between the focal plane array and the pixelated wire-grid polarizer array, both featuring 6.45 μm pixels. An on-chip, four-state, linear snapshot polarimeter is yielded in the detailed processes and raw image data from the instrument are presented.
In this work, we present an analysis of harmonic frequency transmission filters based on one-dimensional photonic crystals using a Fourier transform approach. This approach relates the photonic crystal transmittance with the Fourier transform of the logarithmic derivate of their refraction index profile. We compare this Fourier approach with the exact transmission calculated by means of the transfer matrix method. We study the accuracy of different functions proposed in the literature that relate the Fourier transform of the index profile with the transmittance. This Fourier approach provides a more intuitive understanding of the transmission properties of one-dimensional photonic crystals. We experimentally demonstrate these properties by using coaxial cables of different impedances. This kind of electrical system is easier to perform experimentally and reproduces, in the radiofrequency range, the properties of one-dimensional photonic crystals.