Mach-Zehnder interferometers use optical path difference between optical paths L1 and L2 in the figure.

With the same lengths of L1 and L2 and a transparent sample (solid, liquid, or gas) placed in one optical path, an interference fringe moves in proportion to the extent of the change in the refractive index.

Optical path diagram

Key features

Consisting of mutually independent mirror and beam splitter units that enable broad layout flexibility, Mach-Zehnder interferometers can be used to measure larger samples.

	Points
The Mach-Zehnder interferometer splits an optical path. Make sure no other factors such as convective airflow are present that would generate optical path differences.

Key features of Sigma Koki products

Laser-grade optical elements are essential in devices such as interferometers.

Quality control is critical during manufacturing for processes that impact performance parameters such as transmittance and profile regularity. For example, in lenses and beam splitters that transmit light, heterogeneous portions (striae) in the glass that are not visually apparent can cause local differences in the refractive index. In addition, when theses products are used in transmission or reflection mode, scratches and digs on the element surface can affect measurement--for example, by causing light scattering.

The quality of all materials used in Sigma Koki's optical elements are strictly controlled. Standard products are laser-grade products.