Fabry-Perot Displacement Interferometry

High-resolution Fabry-Perot interferometry is being developed and employed for mechanical displacement metrology, linking optical measurements to the atomic time standard using laser frequency combs.

NIST has recently initiated a program to develop a new standard of electrical capacitance. The approach employs a dynamic electrode geometry in conjunction with precision optical metrology. We will use high-resolution Fabry-Perot interferometry to measure the mechanical displacement of an electrode in a "calculable capacitor," and link the optical measurement to an atomic standard of time by means of a femtosecond-laser frequency comb. This work involves a close collaboration between the Physics Laboratory, Electronics and Electrical Engineering Laboratory, and the Manufacturing Engineering Laboratory.

Activities underway and planned:

*Design and build a new Fabry-Perot interferometer system employing narrow-linewidth telecom lasers and a rubidium frequency reference

*Replace the rubidium reference with a femtosecond-laser frequency comb for greater accuracy