Исследование механизма записи мультиплексных брэгговских дифракционных решеток с планарным вводом-выводом оптического излучения в стеклянных световодах

The article describes the recording of multiplex Bragg diffraction gratings for optical lightguide displays using an optical replication method with a phase mask. The lightguides in the experiment were made of photo-thermo-refractive glass. A photoresist relief-phase diffraction grating was used as a phase mask. Based on angle multiplexing, a compact augmented reality display was implemented.

Моделирование фазовых сдвигов света в порядках дифракционных решеток интерференционного датчика линейных перемещений

Phase shifts of light in the orders of diffraction gratings for the interference sensor of linear displacements are considered. The use of a phase diffraction grating with given geometrical parameters of the surface relief makes it possible to stabilize the phase relationships in the optical signals and, as a result, in the final signals taken from the displacement sensor. Based on mathematical modeling data, technically feasible parameters of the surface relief of diffraction gratings are proposed to create the required phase shifts between the diffracted beams and quadrature modulation signals and to achieve the required measurement accuracy with nanometric resolution.

X-ray diffraction by phase diffraction gratings

The diffraction properties of phase gratings with the periodD= 1.6, 1.0 and 0.5 µm fabricated on an Si(111) crystal by e-beam lithography were studied by triple-axis X-ray diffraction. A 100 nm-thick tungsten layer was used as a phase-shift layer. It is shown that the presence of a grating as a phase-shift W layer on the surface of the Si(111) crystal causes the formation of a complicated two-dimensional diffraction pattern related to the diffraction of X-rays on the phase grating at the X-ray entrance and exit from the crystal. A model of X-ray diffraction on the W phase diffraction grating is proposed.