Diode lasers have several unique capabilities for length-measurement applications, arising from properties of the diodes that are much different from those of the venerable helium-neon laser presently used for most interferometric measurements. For example, the broad tunability of diode lasers makes practical several techniques that are not realistic using other sources. We are studying application of diodes to both large-scale and small-scale length measurements, including wavelength-shifting methods for absolute interferometric measurements of distances on the order of meters and use of a diode laser locked to a Fabry-Perot cavity to achieve picometer resolution of micrometer displacements. Depending on details of the technique, the diode wavelength may or may not provide a wavelength standard in a manner analogous to classical interferometry with a He?Ne laser. We are also exploring use of diode lasers locked to the 657 nm calcium transition as a wavelength standard. This paper reports on the current status of our research.
Proceedings Title: Proceedings of NCSL Workshop & Symposium
Conference Dates: January 1, 1996
Conference Location: Boulder, CO
Pub Type: Conferences
absolute interferometry, calcium stabilized diode laser, external cavity diode laser, feedback, frequency standard, nanometrology, wavelength-shifting interferometry, wavelength-sweeping interferometry