Crossed-cell-tile multiplexed 1st-order gratings, for three-dimensional beam-splitter applications

Oblique angle of incidence two-way and three-way beam splitters were designed and fabricated. The devices feature two first-order diffraction gratings, arrayed crossed in alternating adjacent tiles, resulting in conical diffraction spot separation of two 1^st-orders in orthogonal planes while overlapping the 0^th-order. The two-way beam splitter was designed for 0^th-order suppression. The three-way beam splitter was designed to distribute light equally between the 1^st and 0^th - order spots. Testing of the devices yielded efficiencies of 2%:46%:46% for the two-way beam splitter at 604 nm, and 32%:32%:32% for the three-way beam splitter at 633 nm wavelength. The polarization state of the incident beam was preserved after diffraction through the devices.