In general, an optical cross-connect switching system comprising a switch subsystem, an inputoutput subsystem including a plurality of removable, IO port modules, and a switch control subsystem featuring servo modules. In particular, techniques for using certain transmission at certain frequencies are disclosed for faster thickness and phase determination in an in-line or standalone metrologymonitoring system for CMP processes. The present invention also provides a fuel supply system with a configuration comprising at least one unchoked valve. This arrangement also provides for electric heating of the workpiece when an electric voltage is applied between the two electrodes associated with one of the bifilar conductors. To this purpose, the package stiffener and the electrical conductor may be electrically coupled to the power and ground terminals of the semiconductor package.