OptiSystem component library includes different types of components for WDM systems, the tunable optical filters include Fabry-Perot filters, Mach-Zehnder interferometers, and grating based filters.

Fabry-Perot filters

Fabry-Perot filter.osd shows the transmission of a Fabry-Perot filter used as a tunable optical filter (see Figure 1). The frequency spacing between two successive transmission peaks is know as free spectral range (see Figure 2).

Optical System- Figure 1 - Fabry-Perot Filter

Figure 1:   Fabry-Perot filter

Optical System - Figure 2 - Fabry-Perot filter transmission

Figure 2:   Fabry-Perot filter transmission

Uniform FBG Filters

A separate class of optical filters makes use of the wavelength selectivity provided by a Bragg grating (see Figure 3). FBG filter.osd shows the transmission of a uniform FBG filter (see Figure 4).

Optical System - Figure 3 - FBG filter

Figure 3:   FBG filter

Optical System - Figure 4 - FBG filter transmission

Figure 4:   FBG filter transmission