Physical basis of a holographic interferometer use in photonic telecommunications devices

Abstract

Photonics is a promising direction for improving the equipment of telecommunications systems. In comparison with similar functional electronic devices, products using photonics provide higher performance, a greater dynamic range, both in frequency and in the level of the information signal, reduced energy consumption and noise level, the possibility of varying the parameters and characteristics of the signals in a wide range of values. The possibility of using a holographic interferometer in photonic telecommunications devices is considered. A technology for improving of the technical characteristics of photonic telecommunications devices based on the use of a holographic interferometer that implements the spatial-spectral method of holographic interferometry is proposed. A holographic interferometer of this type is a three-dimensional reflecting-transmitting hologram and a flat mirror placed behind the hologram at a small angle to it, and is an element that is sensitive to the frequency, phase, and curvature of the wave front of a coherent light stream incident in the plane of the interferometer hologram. When these parameters of the light flux change, the parameters of the interferogram generated by the holographic interferometer change accordingly.  The holographic interferogram is formed by the light flux incident on the hologram from the optical emitter and partially diffracted from it, and the light flux partially passed through the hologram, reflected by a flat mirror and partially passed through the hologram of the interferometer in the opposite direction. At the same time, light fluxes with spherical wave fronts are used to form an interferogram. A mathematical model of the formation of this interferogram by a holographic interferometer is constructed. The parameters of the interferometer design are specified, the change of which leads to an   change in the parameters of the interferogram. Mathematical relations are obtained that show a dependence of the interferogram parameters on the spatial position of the phase centers of the real and imaginary point light sources used in the holographic interferometer for the formation of this interferogram. For practical use in photonic telecommunications devices, a mathematical model of the relationship between the parameters of the information electrical signal modulating the luminous flux and the spatial-spectral distribution of the optical field intensity in the plane of the interferogram formed by a holographic interferometer is constructed.