Patent ID: 11956014
Assignee: UNIVERSITA' DEGLI STUDI DI MILANO
Field: Telecommunications (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 18:
19. A system for transmitting and receiving an electromagnetic radiation beam, adapted to determine an orbital angular momentum of the received electromagnetic radiation beam, comprising:
means for generating a main electromagnetic radiation beam, configured to generate a main electromagnetic radiation beam (F1) characterized by a first orbital angular momentum (L1), a first spectrum in a first frequency band, and a first beam radius of curvature;
means for generating a reference electromagnetic radiation beam, configured to generate a reference electromagnetic radiation beam (F0), characterized by a second orbital angular momentum (L0), a second spectrum in a second frequency band which is distinct from said first frequency band, and a second beam radius of curvature substantially coinciding with said first beam radius of curvature;
means for generating a composite electromagnetic radiation beam, configured to generate a composite electromagnetic radiation beam (Q1), consisting of the superposition of said main beam (F1) and reference beam (F2), and means for transmitting a composite electromagnetic radiation beam, configured to transmit said generated composite electromagnetic radiation beam (Q1);
means for receiving the composite electromagnetic radiation beam, comprising:
first beam detection means, located in a first position, configured to generate a first composite beam electrical signal (D1), representative of the electric and/or magnetic field and/or of the intensity of the electromagnetic radiation of the composite beam in said first position;
second beam detection means, located in a second position, which are different with respect to said first position, configured to generate a second composite beam electrical signal (D2), representative of the electric and/or magnetic field and/or of the intensity of the electromagnetic radiation of the composite beam in said second position;
first frequency discrimination means, configured to perform a frequency discrimination of said first composite beam electrical signal (D1) with reference to said first frequency band and second frequency band to obtain, respectively, a first electrical main beam signal (P1), representative of the electric and/or magnetic field and/or of the intensity due to the main beam in said first position, and a first reference beam electrical signal (R1), representative of the electric and/or magnetic field and/or of the intensity due to the reference beam in said first position;
second frequency discrimination means, configured to perform a frequency discrimination of said second composite beam electrical signal with reference to said first frequency band and second frequency band to obtain, respectively, a second main beam electrical signal (P2), representative of the electric and/or magnetic field and/or of the intensity due to the main beam in said second position, and a second reference beam electrical signal (R2), representative of the electric and/or magnetic field and/or of the intensity due to the reference beam in said second position;
means for determining the orbital angular momentum, configured to determine the orbital angular momentum (L1) of the main electromagnetic radiation beam and/or the spatial phase variation of the main electromagnetic radiation beam due to the main beam orbital angular momentum (L1), based on said first main beam electrical signal (P1), second main beam electrical signal (P2), first reference beam electrical signal (R1) and second reference beam electrical signal (R2).