Abstract: A measuring device comprising a base, feet connected to the base, and an inclinometer mounted on the base is used to characterize a surface. The feet are placed in direct contact with the surface at a predetermined position. The inclinometer measures the angle of the surface relative to gravity at the predetermined position. In some embodiments, multiple measuring devices are connected to an arm, in order to measure different positions on the surface simultaneously. The arm may be moved by an actuator to the next predetermined position on the surface. In some embodiments, multiple measuring devices are connected to a frame that is substantially the same size as the surface to be characterized, such that the entire surface can be characterized without moving the frame.

Abstract: A measuring device comprising a base, feet connected to the base, and an inclinometer mounted on the base is used to characterize a surface. The feet are placed in direct contact with the surface at a predetermined position. The inclinometer measures the angle of the surface relative to gravity at the predetermined position. In some embodiments, multiple measuring devices are connected to an arm, in order to measure different positions on the surface simultaneously. The arm may be moved by an actuator to the next predetermined position on the surface. In some embodiments, multiple measuring devices are connected to a frame that is substantially the same size as the surface to be characterized, such that the entire surface can be characterized without moving the frame.

Abstract: A method for producing electromagnetically induced transparency (EIT) in atoms with hyperfine structure. EIT is the phenomenon in which a material (e.g. lead vapor) becomes transparent to a first electromagnetic frequency (a probe beam) when exposed to a second electromagnetic frequency (a coupling beam). In the present invention, the atom has hyperfine split energy levels. In the method of the present invention, the coupling and probe beams are tuned to transitions between the centers of gravity (COGs) of the hyperfine split levels. This allows high transparencies to be achieved in high opacity materials. Also, the present method can produce EIT in isotopically mixed materials. This is because the COGs of hyperfine split levels (in nuclear spin.notident.0 atoms) are generally coincident with nonhyperfine split levels (in nuclear spin=0 atoms). The method of the present invention is directly applicable to nonlinear sum and difference frequency generation.