Interferensmätning

Interferensmätning is a measurement technique that utilizes the phenomenon of optical interference to determine physical quantities. This technique relies on the superposition of two or more light waves, resulting in a pattern of constructive and destructive interference. The observed interference pattern is highly sensitive to variations in the optical path length between the interfering waves. By analyzing these patterns, precise measurements can be made of parameters such as distance, refractive index, surface irregularities, and the thickness of thin films.

The core principle of interferensmätning involves splitting a coherent light source, typically a laser, into two or more beams. These beams are then directed along different paths before being recombined. When the beams recombine, their amplitudes add or subtract depending on their phase difference, which is directly related to the difference in the optical path lengths they have traveled. This phase difference manifests as a series of bright and dark fringes in the resulting interference pattern.

The sensitivity of interferensmätning is exceptionally high, often capable of detecting changes in optical path length on the order of the wavelength of light, which can be as small as a few hundred nanometers. Common interferometric setups include the Michelson interferometer, the Mach-Zehnder interferometer, and Fabry-Perot interferometers, each suited for different applications. These techniques find widespread use in metrology, scientific research, quality control in manufacturing, and the development of advanced optical devices.