Abstract: Various disclosed embodiments provide illustrative interferometers, optical phase locked loops, laser systems, interferometry methods, and phase locked loop methods. In illustrative embodiments, light from a laser is split into a first arm and a second arm. Light in an arm chosen from the first arm and the second arm is time delayed. The light in the first arm is split into third, fourth, and fifth arms. The light in the second arm is split into sixth, seventh, and eighth arms. Light in the seventh and eighth arms is phase shifted relative to light in the sixth arm. Light in the third, fourth, and fifth arms is combined with light in the sixth arm and phase shifted light in the seventh and eighth arms, respectively. A frequency correction signal for the laser is generated.

Abstract: Color separation dichroic mirrors (40,42) positioned between a group of reflective liquid crystal light valves (26,28,30) and a polarization analyzer (14) enable a single projection lens (18) to project all colors via a light beam of single linear polarization with a high degree of contrast, efficiency and color separation. The polarization analyzer (14) directs a light beam with a single polarization state to a pair of dichroic color filters (40,42) which separate the beam into three different colors that are sent to three different reflective liquid crystal light valves (26,28,30). The light valves reflect the respective colored light beams with change of polarization state back to the dichroic mirrors (40,42) which combine the three colors into a single combined multi-color beam that is fed through the polarization analyzer (14) to a single system projection lens (18).

Abstract: A high resolution laminography system for the inspection of integrated circuits wherein a beam of highly focused electrons is traced in a circular pattern on a flat target within a vacuum chamber. The target converts the electron beam into X-rays, so that a source of X-rays is produced which rotates in synchronization with a rotating detector assembly. An object is placed within the vacuum chamber, between the X-ray source and the detector so that an X-ray cross sectional image of a cutting plane of the object is produced. A computer and feedback system controls image acquisition and an automated positioning system. The computer system can also operate under program control to automatically analyze data, measure characteristics of the object under inspection, and make decisions regarding the acceptability of the object's quality.