Abstract: A ring-cavity surface emitting quantum cascade laser (RCSE-QCL) may include a ring-shaped active region having first and second opposing facets. One of the first and second opposing facets may define a radiation emitting facet. The RCSE-QCL may also include a ring-shaped phase shifter aligned with the radiation emitting facet and having a spiraled surface.

Abstract: A ring-cavity surface emitting quantum cascade laser (RCSE-QCL) may include a ring-shaped active region having first and second opposing facets. One of the first and second opposing facets may define a radiation emitting facet. The RCSE-QCL may also include a ring-shaped phase shifter aligned with the radiation emitting facet and having a spiraled surface.

Abstract: An accordion storm shutter assembly includes a frame for installation in an opening in a building wall and a pair of folding shutters which can be drawn together across the opening. Each shutter is formed from a number of blades articulated along vertical edges so that the blades can fold flat when the shutter is open. When the shutter is closed, the blades make a substantial angle with one another, so that the shutter has a corrugated configuration for high impact resistance. Neighboring blades are interconnected by continuous extruded linear hinges, each including a socket which is substantially an arc of a cylindrical shell having a lengthwise gap, and a knuckle adapted to turn within the socket and having a blade arm extending therefrom through the gap. The shutter is intended to provide protection against winds and debris in tropical storms.

Abstract: An accordion storm shutter assembly includes a frame for installation in an opening in a building wall and at least one folding shutter supported by the frame. The shutter is made up of plural blades articulated along their vertical edges so that the shutter can fold from a closed position in which the blades made a substantial angle--about 75.degree.--with one another so as to have a corrugated configuration blocking the opening, to an open position in which the blades are substantially parallel to one another. Neighboring blades are interconnected by continuous, extruded linear hinges, each having a socket which is substantially an arc of each cylindrical shell having a vertical axis. A knuckle formed along one edge of a neighboring blade pivots in the socket.