Interferometers

Introduction

The purpose of an interferometer is similar to that of a filter or monochromator, i.e., to isolate a specific portion of the electromagnetic spectrum. Unlike prism or grating monochromators, interferometers are not dispersive instruments, but use interference to selectively transmit a certain wavelength. The links below lead to descriptions of three interferometer designs.

Types of interferometers

Fabry-Perot interferometer (etalon)

Used in high-resolution applications, such as atomic spectroscopy or measurement of narrow-band laser linewidths.

Michelson interferometer

Used in fourier-transform infrared absorption spectrometers (FTIR).

Mach-Zender interferometer

Used to measure refractive index changes in gases and in interference microscopes to image transparent samples.

Related Topics

• Optics
• Optical Materials