| 摘要 |
A metrology system has one or more central "metrology servers' and one or more "metrology slaves' The server delivers metrology "pump/probe' signals to multiple slave systems allowing a reduction in the number of high-cost metrology components in the master system. In certain cases, multiple metrology components in the "master' system may provide redundancy while still maintaining a beneficial cost benefit. Reliability can also be improved by using multiple lasers and multiple delay paths with a cross-point switch between them. If one sub-system goes down, the system may "serialize' metrology operations and thereby maintain all systems running, although at somewhat of a reduced throughput. An important element of this invention is grouping all or most of the costly components in a centralized laser server, and issuing pump-probe pulse pairs to remote metrology heads through a light pipe or other conveyance, such as optical fiber. The remote metrology heads can thus be reduced in cost and complexity.
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