Abstract: Localized measurement of turbulent airflows is provided using enhanced techniques of digital holography with computed tomography. In an implementation, an optical beam is diffracted to produce an array of signal beams which propagate at different angles through a test volume that includes a test article. A reference beam is optically interfered with the array of signal beams after propagating through the test volume, producing a corresponding array of holograms simultaneously detected by a single digital holographic sensor. Digitized versions of the holograms are processed to produce a signal field for each test beam. Computed tomography is then applied to the signal fields to determine path-resolved turbulence measurements.

Abstract: A database command replacer intercepts database commands to one or more database servers, extracts the database command and defined parameters within the command, and determines if the database command is defined in the list of commands subject to replacement; if not, the command is passed through to the destination database server. If the database command is in the list of commands subject to replacement, the replacement command is retrieved, the mapped parameter values are incorporated into the replacement command, the replacement command is transmitted to the destination database server, and the resultant information is relayed back to the origination program. No changes are required to either the client or server software in existing client/server database arrangements.

Abstract: A mode-locked laser (MLL) that produces ultra-low phase noise optical and RF outputs, includes two nested resonant optical cavities including an optical fiber-based cavity and an etalon, and a three bandwidth Pound-Drever-Hall (PDH) frequency stabilizer assembly incorporating three different optical bandpass filters. The optical fiber-based cavity is characterized by a free spectral range, FSRfiber, and the etalon is characterized by a free spectral range, FSRfilter, wherein FSRfilter/FSRfiber is an integer equal to or greater than 2. A method of generating ultra-low phase noise optical and RF outputs is disclosed. Optical and RF outputs have a phase noise that is less than ?100 dBc/Hz at 1 Hz and less than ?150 dBc at 10 KHz.

Abstract: A mode-locked laser (MLL) that produces ultra-low phase noise optical and RF outputs, includes two nested resonant optical cavities including an optical fiber-based cavity and an etalon, and a three bandwidth Pound-Drever-Hall (PDH) frequency stabilizer assembly incorporating three different optical bandpass filters. The optical fiber-based cavity is characterized by a free spectral range, FSRfiber, and the etalon is characterized by a free spectral range, FSRfilter, wherein FSRfilter/FSRfiber is an integer equal to or greater than 2. A method of generating ultra-low phase noise optical and RF outputs is disclosed. Optical and RF outputs have a phase noise that is less than ?100 dBc/Hz at 1 Hz and less than ?150 dBc at 10 KHz.