Development status of a four-channel CWDM system for Multi-Gbit/s in-house data communication via SI-POF

Inhalt:
The polymer optical fiber (POF) offers certain advantages over alternative data communication media such as glass fibers, copper cables or wireless systems. Due to its advantages, POF is a promising candidate for broadband in-house networks. Among different types of POF, the standard 1-mm step-index POF (SI-POF) is the best known and by far the most widely used type of POF. However, the SI-POF suffers from high attenuation and strong inter-modal dispersion. To extend the capacity of the SI-POF link multiple optical carriers can be used for parallel transmission of communication channels over the same fiber. This paper reports on the current development status of a four-channel coarse wavelength division multiplexing (CWDM) transmission system for the investigation of Multi-Gbit/s data links via SI-POF. The key photonic WDM components were realized at the Harz University. For combining the optical signals coming from violet, blue, green, and red laser diodes (LDs) onto 1-mm SI-POF, a 4:1 coupler with low insertion loss (IL) was developed. To spatially separate different wavelength channels, a four-channel demultiplexer (DEMUX) with low IL (< 5.7 dB) and low crosstalk (< -30 dB) was realized in the bulk optics technology. The non-return-to-zero (NRZ) modulation was used in combination with offline-processed feed-forward equalization (FFE) to demonstrate the 10.7 Gbit/s four-channel WDM transmission over 25 m SI-POF link at a bit error rate (BER) of less than 10^-3.