Abstract: An optical switch for controllably switching an interface between a reflective state in which incident light undergoes total internal reflection and a non-reflective state in which total internal reflection is prevented. In one such switch a cell contains a fluid. One side of the cell forms the light incident interface. A membrane is suspended in the fluid. One pair of electrodes is applied to opposite sides of the membrane. Another electrode pair is applied to the cell's interface side and to the cell's opposite side. A variable voltage potential is applied between selected ones of the electrodes. Application of the voltage potential between selected ones of the membrane and cell electrodes moves the membrane into optical contact with the interface, producing the non-reflective state. Application of the voltage potential between other selected ones of the membrane and cell electrodes moves the membrane away from optical contact with the interface, producing the reflective state.

Abstract: An optical switch for controllably switching an interface between a reflective state in which incident light undergoes total internal reflection and a non-reflective state in which total internal reflection is prevented. In one such switch a cell contains a fluid. One side of the cell forms the light incident interface. A membrane is suspended in the fluid. One pair of electrodes is applied to opposite sides of the membrane. Another electrode pair is applied to the cell's interface side and to the cell's opposite side. A variable voltage potential is applied between selected ones of the electrodes. Application of the voltage potential between selected ones of the membrane and cell electrodes moves the membrane into optical contact with the interface, producing the non-reflective state. Application of the voltage potential between other selected ones of the membrane and cell electrodes moves the membrane away from optical contact with the interface, producing the reflective state.

Abstract: An optical switch for controllably switching an interface between a reflective state in which incident light undergoes total internal reflection and a non-reflective state in which total internal reflection is prevented. In one such switch an elastomeric dielectric has a stiffened surface portion. A separator positioned between the interface and the stiffened surface portion maintains a gap there-between. A voltage source applies a variable voltage potential between electrodes on the interface and stiffened surface portion respectively. The applied voltage potential moves the stiffened surface portion into optical contact with the interface, producing the non-reflective state. In the absence of a voltage potential the separator moves the stiffened surface portion away from optical contact with the interface, producing the reflective state. In another such switch a cell contains a fluid. One side of the cell forms the light incident interface. A membrane is suspended in the fluid.

Abstract: Charged particles suspended in a medium such as Fluorinert™ Electronic Liquid are used to electrophoretically control total internal reflection (TIR) at a retro-reflective surface formed on a high refractive index material. Prismatic structures redirect ambient light from an overhead light source toward a display image and then from the image to the region in front of the image, yielding a high contrast reflective display. A transparent planar waveguide front lights the display with sequential flashes of red, blue and green light to generate a full color display. TIR can also be controlled at retro-reflective surfaces by means of a vapor-liquid phase transition, or by changing the absorption coefficient of a material using electrical, chemical and/or electrochemical methods.

Abstract: A cryogenic detector comprises an array formed from a plurality of spherical grains made of type I superconducting material arranged in a preselected pattern and each having a preselected size (generally less than about 100 microns in diameter). Also disclosed is a method of making such an array by depositing a film of selected thickness of type I superconducting material on a substrate, etching the film to provide an array formed by a plurality of discrete pixels, melting the pixels under conditions whereby the pixels are transformed into substantially spherical shape, and cooling to freeze the molten pixels into substantially spherical grains.