A -- Developments At NIST

Researchers at the National Institute of Standards and Technology (NIST) are working on the following technologies. For further information, contact the: National Institute of Standards and Technology, Office of Technology Partnerships, 100 Bureau Drive, Stop 2200, Gaithersburg, Maryland 20899; Fax: +1 (555) 000-0000. This is not an announcement of a contract action or a grant.NIST DOCKET NUMBER: 01-012PA Title: System And Method For Privilege Management Of Mobile Agents Description: A general-purpose mechanism is described for controlling the behavior of mobile agent-system entities, both human and software, through allocation of privileges. Privileges refer to policy rules that govern the access and utilization of computational resources and services. The invention is based on the capability of most mobile agent systems to extend the platform processing environment and the use of two forms of privilege management certificates: attribute certificates and policy certificates. Privilege management certificates are digitally signed objects that allow various policy setting principles to govern the activities of mobile agents through selective privilege assignment. The invention overcomes a number of problems in existing agents systems and provides a means for attaining improved interoperability of agent systems designed and implemented independently by different manufacturers. NIST DOCKET NUMBER: 01-030PA2 Title: Minimizing Spatial-dispersion-induced Birefringence in Crystals Used For Precision Optics By Using Mixed Crystals of Materials With the Opposite Sign of the Birefringence Description: The intrinsic birefringences we recently discovered, by measurement and calculation, in CaF2 and BaF2 crystals present serious problems for use of these crystalline materials for precision optics in the ultraviolet (UV), e.g., for UV optical lithography. Since we found the intrinsic birefringences of CaF2 and BaF2 have opposite sign, we propose a correction solution in which a mixed crystal Ca1-xBaxF2 is made which effectively zeroes out the birefringence of the crystal at a given wavelength, for an appropriately chose value of x. The appropriate x value is determined approximately by the mixture where the linearly interpolated birefringence goes to zero. Our calculations indicate the SrF2 has a birefringence that is also opposite in sign to that of CaF2. In this case a mixed crystal Ca1-xSrxF2 could also have zero birefringence. Optical components such as lenses and beam splitters could be made of these mixed crystals that would be free of intrinsic birefringence aberrations at a chosen wavelength. These could be used as components of precision optical systems at this wavelength, such as optical photolithography projection systems.