Selection Features of Different Standard Optical Fiber in CCTV Fiber-Optics Systems

Abstract

The high-quality video signal has a wide spectrum typically. Therefore, in order to transmit such a signal over long distances through an optical cable, low-loss, low-dispersion optical fiber is required. In fiber-optic video systems, as well as in optical communication systems, standard single mode optical fibers (SSMF, standard G 652) are usually used. One of the advantages of these fibers is the ability to use CWDM in a wide spectrum (from 1270 to 1610 nm). At the same time, non-zero dispersion fiber (NZDSF, standard G 655) is more optimal near the wavelength of 1550 nm. However, as studies have shown, these optical fibers have an increased sensitivity to bending. This fact can be used to traffic interception. In WDM-system, for example, CWDM, due to nonlinear effects in fiber the part of the optical power from the working channel can enter the adjacent channels. Computer simulation of the four-wave multiplexing (FWM) effect in CWDM-system has been carried out. It is shown that fiber-optics systems with SSMF have more protection from traffic interception than systems with NZDSF. To transmit a high-confidential video signal, special techniques, such as frequency modulation, can be used, or additional noise signals can be added.KeywordsVideo systemsSecurity systemsFiber-optic cables