VERIFICATION OF A POLARIZATION-INSENSITIVE OPTICAL INTERFEROMETER SYSTEM WITH SUBNANOMETRIC CAPABILITY

The performance of a length-measuring interferometer system designed t o be insensitive to stray reflections and polarization effects resulti ng in a subnanometric measurement capability is described. Results fro m the mathematical analysis of the interferometer signals, which provi ded accurate fringe subdivision and allowed a 1 sigma of 0.15 nm to be realized from this system, are also described. The motion of a piezoe lectric transducer (PZT) was characterized over a 1-mu m range using t he system, and the results were used to confirm this subnanometric mea surement capability of the interferometer.