Secured high volume free space optical communications based on computer
generated holograms.




The objective of this project is to realize and thoroughly test a functional model of a free space optical communication system based on optical vortex encoding for turning this novel concept into a potential emergent secured high volume information transfer technology.

Specific objectives

SO1 Realization of high quality phase masks for both generating OV with well defined OAM numbers and high diffraction efficiency as well as for sorting. This objective is a complex one encompassing activities of design using numerical algorithms, simulation with dedicated software, optimizations of micro/nanofabrication processes like 3D electron beam lithography, morphological characterizations (AFM,SEM, etc), and optical characterizations.

SO2 Realization of the optical setup: The key feature of the functional model will be the superposition of several optical vortices on the same laser beam since an increase in the number of superimposed OV will lead to a corresponding increase in the aggregate volume of transmitted information. The integration of diffractive optics with the conventional one will be addressed and activities like design, optical experimentation as well as simulations using

SO3 Realization of electronic modules: electronics providing low-rate modulation for testing the proof of concept as well as high – rate modulation for the functional model will be designed and realized. Special attention will be given to the interfacing of the electronic modules with computers. Also in this context, various electronic information encoding schemes will be studied in order to find the best modality to modulate the OV for attaining the highest volume information transfer over the free space link.

SO4 Realization and testing the functional model: This objective aims to integrate the electronic modules with the optical setup for the realization of a OV based FSOC system. The functionality of the model is a measure of success for the project. After the system is realized, a series of tests like the determination volume of the transmitted information as a function of the number of vortices, and the verification of the data integrity will be performed. Scalability studies in terms of number of superimposed OV, the values of OAM, increase of the bit rate modulation will be conducted. The secure nature of information transmission will be investigated.