Światłowodowy demodulator fazy na bazie całkowania przestrzennego w układzie światłowodowego interferometru Younga

W artykule zaprezentowano eksperymentalne wyniki badań światłowodowego demodulatora fazy w układzie interferometru Younga. Pokazano, że poprzez odpowiednie całkowanie widmowej gęstości mocy w płaszczyźnie Fouriera istnieje możliwość jednoznacznego określenia różnicy faz w obu światłowodach w zakresie od 0 do 2π.

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Experimental results of investigation a new fiber-optic phase demodulator operating in the Young interferometer configuration are the main subject of this paper. The experimental set-up contains set of two single mode optical fibers with collimators and rectangular prism for protecting the coherent beams coupling. Next a lens has been used for the optical Fourier transform realization. In this way, a spectral power density in Fourier back focal plane is spatial modulated, with frequency depended among other things on distance between fibers. The proper spatial integration of the output filed, for instance by using the two elements photodetector, the unambiguous information about phase changes in the range from 0 to 2π can be obtained by proper signal processing. The paper presents the experimental results which are in good agreements with theoretical model. Because the CCD element has been used in the presented experiment, the detected plane has been divided on two parts by special numerical procedure. Finally, the application commercially available multi-elements photodetector will protect above procedure in a hardware way.