Construction of a Phase-Locked Loop System Using Holographic Photonics

Abstract

The problem to construct a photonic phase-locked loop (PLL) system using a volume reflective hologram is considered. The technical characteristics of any telecommunications equipment crucially depend on the stability of the frequencies of the output oscillations of its generating equipment. Realization of the photonics capabilities in construction of modern PLL systems is relevamt direction for improving their technical characteristics. The highest technical characteristics are possessed by photonic devices that use holographic structural elements. The article presents and describes a variant of the structural diagram of a photonic PLL system with a volume reflective hologram in its design. A mathematical model of the process of forming an interferogram in this system is developed and investigated. In the structural diagram of the holographic photonic PLL system, the curvature of the spherical wave fronts of two coherent light fluxes is modulated with electrical signals. It is shown that the interference of light fluxes modulated in this way forms an interferogram, which parameters unambiguously correspond to the phase difference of the output oscillations of the reference and adjustable generators. The work determines the sensitivity of the parameters of this interferogram to the spatial position of the phase center of a light flux source with a spherical wavefront (focal point of this light flux), modulated by an electrical signal proportional to the output signal of an adjustable generator of the PLL system. A valid conclusion is made that practical implementation of a holographic photonic PLL system with improved technical characteristics is possible.