FIBER OPTIC TRANSMISSION OF RGB-SIGNALS USING A WDM SYSTEM Lyubomyr V. Bartkiv and Yaroslav V. Bobitski Department of Photonics, Lviv Polytechnic National University 12 Stepana Bandery Str., 79013, Lviv, Ukraine E-mails: lbartkiv@polynet.lviv.ua, bobitski@polynet.lviv.ua Abstract-Wavelength-division-multiplexing (WDM) is one of the best technologies for improving of transmis- sion performances of optical communication links. In this work the fiber optic interface for transmission of RGB-signals using a WDM system is presented. The recent WDM technologies are considered in details with special emphasis on their advantages and disadvantages. Those WDM technologies which are most suitable and cost-effective for the system of transmission of RGB-signals have been selected. Keywords: fiber optic transmission, RGB-signals, WDM components INTRODUCTION There are many various applications which require a long distance transmission of video images generated by a PC. Analog RGB-signals are commonly used for carrying of video information from PC to a monitor. The bandwidth of these signals strongly depends on the screen resolution and frame frequency. For connecting of a monitor to the PC a standard VGA cable is commonly used. Its maximum length is defined by the bandwidth of RGB-signals and is limited to a few meters only. For longer transmission distances a twisted pair cable is used [1]. Nevertheless, some applications still require longer transmission lengths which can not be achieved using twisted pair cables. Another problem is appeared if working in surroundings with high electromagnetic disturbances which result in picture quality deterioration. All those problems mentioned above are missing in transmission systems based on an optical fiber. Many kinds of similar fiber optic systems are available on the market [2-4]. Their fiber optic interfaces mainly use three optical fibers through which three RGB-signals are transmitted independently of one another. An attempt to improve this interface using a 3-channel POF- WDM system has been realized in [5]. One important feature of wavelength-division- multiplexing (WDM) technology is that it gives a possibility to transmit many different signals simultaneously over a single fiber. The new interface consists of only one fiber and two additional devices – WDM multiplexer and demultiplexer (MUX and DEMUX) – which are intended for combining and separating of RGB-signals, respectively. As was indicated in that paper, the optical losses of WDM devices were the main reason of high system losses. Therefore, in this work the transmission of RGB-signals using a WDM system will be considered and the main attention will be given to the WDM MUX and DEMUX. FIBER OPTIC INTERFACE The new fiber optic interface generally consists of three major parts – transmitter, receiver and optical fiber cable – as shown in Figure 1. Video RGB-signals from the VGA adapter of a PC are supplied to the transmitter. Electro/Optical converter transforms these high-bandwidth analog RGB-signals into optical ones with different wavelength carriers which are combined later in a single beam by WDM MUX. After transmission through an optical fiber the light beam carrying combined optical signal is separated into its spectral components by WDM DEMUX. Opto/Electrical converter transforms these optical signals into electrical ones. Finally, restored RGB-signals are transmitted to the monitor. CAOL 2005, 12 – 17 September 2005, Yalta, Crimea, Ukraine 257 0-7803-9130-6/05/$20.00 © 2005 IEEE