Measurement of gauge blocks by interferometry

Electron density measurement by differential interferometry

A novel differential interferometer is being developed to measure the electron density gradient and its fluctuations. Two separate laser beams with slight spatial offset and frequency difference are coupled into a single mixer making a heterodyne measurement of the phase difference which is 1% of the total phase change experienced by each beam separately. This measure of the differential phase ...

Gauge Blocks – A Zombie Technology

Gauge blocks have been the primary method for disseminating length traceability for over 100 years. Their longevity was based on two things: the relatively low cost of delivering very high accuracy to users, and the technical limitation that the range of high precision gauging systems was very small. While the first reason is still true, the second factor is being displaced by changes in measur...

Gauge fields and interferometry in folded graphene

Diego Rainis,1,* Fabio Taddei,1 Marco Polini,1,2 Gladys León,1,2 Francisco Guinea,3,2 and Vladimir I. Fal’ko4,2 1NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56126 Pisa, Italy 2Kavli Institute for Theoretical Physics China, CAS, Beijing 100190, China 3Instituto de Ciencia de Materiales de Madrid (CSIC), Sor Juana Inés de la Cruz 3, E-28049 Madrid, Spain 4Physics Department, La...

Measurement of the electric polarizability of lithium by atom interferometry

Measurement of surface topography of magnetic tapes by Mirau interferometry.

Stylus-profiling techniques cannot be used for surface characterization of polymeric surfaces, such as magnetic tapes, because of their relatively low hardness An interferometric-optical-profiling microscope system was used to obtain high-accuracy surface profiles of magnetic media, rapidly and without physical contact with the sample. The profilometer consists of a conventional, reflection-typ...