optical device demultiplazione and multiplexing frames of a cultural channels with different length d? wave and different angular momentum on orbital and optic communication system

摘要

It is disclosed an optical device (1) for demultiplexing a plurality of channels with different wavelength (λ1, λ2, λ3) and different orbital angular momentum (I1, I2, I3). The device comprises a first diffractive optical element (1 -1 ) for performing a wavelength division demultiplexing and a second diffractive optical element (1 -2) for performing a mode demultiplexing. The first diffractive optical element (1 -1) is configured to receive a multiplexed incident optical beam (F_i_mux) carrying the plurality of channels having a plurality of different values of the wavelength (λ1, λ2, λ3) and a plurality of different values of the orbital angular momentum (I1, I2, I3), and is configured to generate at the output, as a function of the multiplexed incident optical beam (F_i_mux), a plurality of first free space circular optical vortices (FO1_SL, FO2_SL, FO3_SL) having respective wavefronts with different radii of curvature which depend on the plurality of different values of the wavelength, wherein each of the first free space circular optical vortices carries said plurality of different values of the orbital angular momentum. The second diffractive optical element (1 -2) comprises a plurality of zones (Α1, A2, A3) equal to the plurality of different values (λ1, λ2, λ3) of the wavelength. Each zone is configured to receive at the input a respective first free space circular optical vortex (FO1_SL) carrying said plurality of different values of the orbital angular momentum, and is configured to generate at the output, as a function of the respective first free space circular optical vortex (FO1_SL), a plurality of second free space circular optical vortices (FO1.1_SL, FO1.2_SL, FO1.3_SL) oriented in different directions in the space which depend on the plurality of different values of the orbital angular momentum, wherein the plurality of the second free space circular optical vortices generated by the respective zone carries a same value of the wavelength and a different value of the orbital angular momentum.