Combined implementation of controllable beam splitting and wavelength division multiplexing using tunable interference wedged structures

The focus of the work is on development and implementation of competitive optical elements based on tunable interference wedged structures. Such a structure can be a single interference wedge (two reflecting surfaces separated by a gap with increasing thickness) or a composition of two or more superimposed wedged layers with adjusted parameters. We used these structures to build a new wavelength division multiplexing (WDM) element and realized coupling of these elements with a fiber optical system as an issue of essential interest for optical communications. Under illumination with a multi-wavelengths beam, the composed WDM structure in the fiber system provides precisely controllable wavelength selection (resolution better than 0.01 nm) within the range of more than 15 nm and with controlled continuously variable transitivity from 1-3 to 80 %. The non-transmitted power with the other non-selected and completely reflected light is directed to the next output (theoretical loss of the system ~ 5 %). The WDM-structure works at completely independent spectral selection of each output/input without any influence between the tuning of the channels.