Double-stage phase-diversity optical receiver: analysis and experimental confirmation of the principle

The double-stage phase-diversity (DSPD) scheme features phase-diversity-type optical homodyne detection and phase-diversity-type frequency up-conversion, producing a heterodynelike second intermediate frequency (IF) signal. It has the advantages of both heterodyning and homodyning and is applicable not only to optical, but also to all the electrical and radio communications ranging from VLF to millimeter-wave frequencies. The theoretical analysis of the receiver performance and the experimental confirmation of the principle of the DSPD scheme are described