Three Dimensional Acousto-Optics Cell Array (AOCA) Systems for MUX/DEMUX Application in Dense Wavelength Division Multiplexing (DWDM)

The acousto-optically tuned devices are already being used in high speed and high capacity DWDM systems as modulator, frequency shifter, deflector and filter in modern optical communication. Recently the acousto-optic cell array (AOCA) system has been investigated for Multiplexer/Demultiplexer (MUX/DEMUX) application in DWDM technology. In this research, the three dimensional acousto-optic cell array (AOCA) systems have been investigated for MUX/DEMUX and cross connect applications in DWDM. An acousto-optic cell (AOC) works on the principle of acousto-optic-effect. The interaction of the optical signal and the acoustic wave in an anisotropic material like LiNbO3 produces the periodic modulation of the index of refraction. Layers of different refractive indices diffract the light beam. An acousto-optic cell (AOC) offers low insertion loss, less cross talk, and is free from the grating wavelength drift due to thermal variations. Therefore, AOC is used in optical information processing and various DWDM networks. The diffraction efficiency of a single acousto-optic cell is quite low and it cannot provide sufficient deflection to match the location of optical fiber at the MUX/DEMUX output. Hence, acousto-optic cell array (AOCA) system is used to produce very high diffraction efficiency. The acousto-optic cell diffraction is preferred over other systems as the acousto-optic cell diffracts the optical beam depending on the wavelength and acoustic frequency which can be controlled electronically. The simulation and analytical results for deflection angles in x, y and z directions for several stages have been obtained. Further, the variations of deflection angles with wavelength, incident angle and RF signal frequency have been demonstrated in this research.