Abstract: A Hartmann inspection system is provided that includes, comprising: a laser source; and a spatial light modulator (SLM) configured to form at least one aperture to form an object beam for inspecting an object, wherein the SLM is further configured to modulate the aperture with a diffraction grating.

Abstract: A system for quantifying surface characteristics detects and quantifies characteristics of a surface of an object. For example, the system may quantify changes in surface roughness without contacting the specimen and without requiring precise temporal or spatial stability. The system may also quantify the evolution or progression of a particular characteristic of a surface, such as a defect, a slipband, a crack, a microcrack, a pit, a damage feature, corrosion, a contour change, an impact crater, a change in residual stress, and so on. The system may include an energy source, a detector section, and a process section. The energy source transmits a source signal to the surface of the object. The source signal is specularly reflected and/or scattered by the surface to yield one or more received signals. The detector section receives the received signal and, in turn, provides a detector signal indicative of the received signal.

Abstract: A holographic security label and automated reading machine for marking and subsequently authenticating any object such as an identification badge, a pass, a ticket, a manufactured part, or a package is described. The security label is extremely difficult to copy or even to read by unauthorized persons. The system comprises a holographic security label that has been created with a coded reference wave, whose specification can be kept secret. The label contains information that can be extracted only with the coded reference wave, which is derived from a holographic key, which restricts access of the information to only the possessor of the key. A reading machine accesses the information contained in the label and compares it with data stored in the machine through the application of a joint transform correlator, which is also equipped with a reference hologram that adds additional security to the procedure.

Abstract: An improved folded cavity laser having particular application to holographic imaging is disclosed. The laser includes a lasing medium, such as for example a ruby rod, which is optically or electronically "pumped" in order to provide laser light. The medium includes first and second optical surfaces disposed at opposite ends of the lasing medium. A retro-reflecting roof mirror is disposed in optical alignment with the second optical surface of the lasing medium. A transverse mode selector is provided in optical alignment with the first surface of the lasing medium in order to surpress all transverse modes except those of a desired character. In the present embodiment, the transverse mode selector includes two apertures of approximately two millimeters diameter in order to obtain a laser output with a TEM.sub.00 mode.