Overview of the measuring systems where a continuously altered light source plays a key role- Part II.

The paper concentrates on the micro-interferometric techniques that utilizes a light source of the continuously altered wavelength. The technique is called, after the light source, the variable wavelength interferometry. It can be implemented in transmitted or reflected-light modes and is useful in testing fibers, micro-structures and optical elements like retarders (waveplates). The emitted spectrum has to be continuous. When the measurement procedure advances the selected wavelength must be determined with high accuracy, which ultimately defines uncertainty of the optical path difference to be measured. The continuous character of the light source is the linking element with previously published Part I of the paper that focused on confocal sensors.