Experimental Verification of a Bigrating Beam Rider.

An optical beam rider making use of a light sail comprising two opposing diffraction gratings is experimentally demonstrated for the first time. We verify that the illuminated space-variant grating structure provides an optical restoring force, exhibiting stable oscillations when the bigrating is displaced from equilibrium. We further demonstrate parametric cooling by illuminating the sail with synchronized light pulses.

Rapidly tunable HIP treated Cr:ZnSe narrow-linewidth laser.

A narrow - linewidth, hot isostatic treated Cr:ZnSe laser was non - mechanically tuned over a total wavelength range of 195 nm by a novel organic liquid crystal etalon. The narrow - linewidth laser was continuously tuned by applying a 1 kHz square wave signal of 1 - 5 V to the intracavity 9 THz nominal free spectral range liquid crystal etalon. The maximum and minimum lasing wavelengths were 2650 nm and 2455 nm, respectively, and a maximum average output power of 475 mW was recorded at 2503 nm.

A common-path polarization-based image-inversion interferometer.

We present a collinear, common-path image-inversion interferometer using the polarization channels of a single optical beam. Each of the channels is an imaging system of unit magnification, one positive and the other negative (inverted). Image formation is realized by means of a set of anisotropic lenses, each offering refractive power in one polarization and none in the other.

Parallel sorting of orbital and spin angular momenta of light in a record large number of channels.

Parallel sorting of orbital and spin angular momentum components of structured optical beams is demonstrated. Both spin channels are multiplexed within the novel orbital angular momentum (OAM) sorter, reducing the size, weight, and number of elements. The sorted states are linearly spaced over 70 topological charge values.

Hidden Gratings in Holographic Liquid Crystal Polymer-Dispersed Liquid Crystal Films.

Dynamic diffraction gratings that are hidden in the field-off state are fabricated utilizing a room-temperature photocurable liquid crystal (LC) monomer and nematic LC (NLC) using holographic photopolymerization techniques. These holographic LC polymer-dispersed LCs (HLCPDLCs) are hidden because of the refractive index matching between the LC polymer and the NLC regions in the as-formed state (no E-field applied). Application of a moderate E-field (5 V/μm) generates a refractive index mismatch because of the NLC reorientation (along the E-field) generating high-diffraction efficiency transmission gratings.