Title :
Comparison of Intersymbol Interference Power Penalties for OOK and 4-PAM in Short-Range Optical Links
Author :
Szczerba, Krzysztof ; Westbergh, P. ; Agrell, Erik ; Karlsson, Magnus ; Andrekson, Peter A. ; Larsson, A.
Author_Institution :
Dept. of Microtechnol. & Nanosci., Chalmers Univ. of Technol., Goteborg, Sweden
Abstract :
We present results of experimental and theoretical investigations of intersymbol interference in 4-PAM transmission in short-range optical communications links based on the power penalty. A test link comprised of a directly modulated 850 nm VCSEL with up to 200 m of multimode fiber and direct detection was used. The link bandwidth was below 10 GHz and the maximum achieved data rate with 4-PAM was 44 Gbps over 100 m of fiber. In the same case and at similar sensitivity, only 32 Gbps could be achieved with OOK. If typical forward error correction could be applied, the sensitivity of the 4-PAM system was improved by up to 4 dB, reaching -10 dBm at 25 Gbps.
Keywords :
amplitude shift keying; forward error correction; intersymbol interference; optical communication equipment; optical fibre communication; optical modulation; surface emitting lasers; 4-PAM; OOK; VCSEL; bit rate 25 Gbit/s; bit rate 32 Gbit/s; bit rate 44 Gbit/s; direct detection; forward error correction; intersymbol interference power penalties; multimode fiber; short-range optical communications links; wavelength 850 nm; Bit error rate; Frequency measurement; Modulation; Optical fiber communication; Optical sensors; Sensitivity; Vertical cavity surface emitting lasers; 4-PAM; 850 nm; IM/DD; MMF; OOK; VCSEL; data communications; fiber-optical communications; interconnects intersymbol interference; short-range;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2013.2285468
