Abstract: The invention provides a method of bonding an optical element within an enclosure, the method comprising providing an optical element within an enclosure having interior walls configured and sized to surround the exterior walls of the optical element with clearance, so as to form a space therebetween; introducing into the space members having a cross-section substantially the same as the cross-section of the space at the locations of the members; filling the space with adhesive which does not adhere to the members, and removing the members, forming air-filled voids which cause the reduction of stress in the optical element when its temperature changes. The invention further provides an optical system to be used in the described method.

Abstract: The invention provides a thermal switch, including a frame made of electrically insulating material, defining the perimeter of a cell fillable with liquid crystal (LC); first and second plate-shaped electrodes, each having an inside surface and an outside surface and being attached along the periphery of the inside surface on opposite sides of the frame, defining surfaces of the cell; first and second covers made of electrically insulating material, each attached to the outside surface of one electrode, the inside surface of at least a portion of each of the electrodes being treated to obtain anchoring of the orientation of LC molecules in a direction parallel to the plane of the electrode, resulting in improved performance of the switch.