Interferensmåling

Interferensmåling is a measurement technique that utilizes the principle of optical interference to determine physical quantities. This method relies on the superposition of two or more light waves, typically from a coherent source like a laser. When these waves combine, their amplitudes can either add up constructively, resulting in a brighter spot, or cancel each other out destructively, leading to darkness. The resulting pattern of bright and dark fringes is highly sensitive to even minute changes in the optical path lengths of the interfering beams.

By introducing a sample or altering the environment in a way that affects the optical path, the interference pattern shifts. Interferensmåling involves precisely measuring these shifts. For instance, in optical interferometers like the Michelson interferometer, one beam travels through a reference path, and the other travels through a path influenced by the quantity being measured. The difference in these path lengths, which causes a change in the interference pattern, is directly proportional to the measured quantity. This technique is employed in various fields, including metrology for precise length measurements, materials science for surface analysis and defect detection, and in the development of sensitive sensors for detecting changes in pressure, temperature, or refractive index. The accuracy of interferensmåling is a significant advantage, allowing for measurements at the nanometer scale.