Transverse-periodic-oriented nematic liquid crystals (LCs) are a special type of optical axis grating that are capable of very high efficiency diffraction (theoretically, 100%) in thin layers of materials with thickness comparable to the radiation wavelength. In particular, they fully diffract linearly polarized input beam into circularly polarized +1st and -1st diffraction orders. We experimentally demonstrate switching between diffraction orders of such gratings when the polarization of the incident beam changes from right-circular to left-circular and vice versa with the aid of an electrically controlled LC phase retarder. Such a setup in which the diffraction efficiency and direction are controlled externally, without application of an electric field to the transverse-periodic grating, provides additional control opportunities and does not compromise the quality of the grating. The grating used in the experiment was 1.5 microm thick and had a period of 4 microm. The contrast ratio of switching between the +1st and -1st orders was as high as 267:1 for a He-Ne laser beam with a switching time of 6.6 ms.

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Permanent binary phase masks with planar surfaces and high tolerance to laser radiation are recorded in the volume of photo-thermo-refractive glass using the contact copying technique and binary amplitude master masks. Conversion of a Gaussian beam to higher order modes is shown.

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Fast electrooptic (EO) deflector switches (DSs) have high potential for applications in optical burst transport networks. EO properties of active materials used in the DSs can impose some limitations on their beam deflection efficiencies. Using a test setup with planar silica waveguide microlens arrays, thin-film ferroelectric oxide beam deflectors, and glass volume Bragg gratings, we demonstrate that the beam deflection angle can be increased by more than a factor of 5 for the same switching voltages. The technology enables significant performance improvement of the fast EO DSs.