Tap couplers are typically used to split one beam into separate transmitted and reflected beams with a well controlled optical power ratio. They are used primarily for monitoring the optical fiber traffic in telecom applications.
Iridian specializes in providing custom tap coupler/beamsplitter filters with accurate tap ratio and polarization status. These filters can be designed to work either with a polarized or non-polarized input beam and the output beams may be polarized or not, as desired. While most beamsplitters require a flat transmittance/reflectance level over a broad wavelength range, Iridian can also design beamsplitters with non linear responses if required.
Some product examples can be found on this page.