What are the common types of optical spectrum analyzers?

There are several common types of optical spectrum analyzers used in laboratories and industries. The most popular type is the diffraction grating based analyzer. It separates light into different wavelengths using a grating and provides accurate measurements. Another common type is the Fabry Perot interferometer-based analyzer. It uses interference of light waves to measure very narrow spectral lines. A third type is the Michelson interferometer-based analyzer, which is often used in Fourier Transform Optical Spectrum Analyzers. These can measure wide ranges of wavelengths quickly. Some modern analyzers are based on acoustic optic filters, which use sound waves to control light. Each type has advantages depending on the required accuracy, resolution, speed, and wavelength range of measurement.