An analytical model for evaluating the performances of PMD-supported dual-channel, direct-detection optical
PolSK transmission systems with a simple-structure, pre-amplified receiver is presented. The BER in each
channel and an average BER of the system are evaluated based on the calculations of the noise probability
density functions by using the Karhunen-Lo`eve expansion and moment generating function. The PMD effects
in the fiber link are taken into account. Based on the proposed model, the calculated results for evaluating
performances of the PolSK system are presented.
In this paper, we present the simulation results on the investigation of the impacts of PMD on the PolSK optical
transmission system. The model used for this study is a dual-channel, direct-detection PolSK optical transmission system
with improved receiver architecture. The quality Q factor of system is used as a parameter to evaluate quantitatively
PMD effects on the performances of this dual-channel PolSK system. The simulation results show that the PMD severely
impairs the transmission performances of the PoLSK system and resultantly limits the bit rate. The results also show that
with PMD compensation, the performances of the PolSK system can be effectively improved and the bit rate increases
greatly from 6 Gb/s to 22 Gb/s.
We present a novel FBG moisture sensor system using a SOA-based fiber laser with two FBG sensors as resonator
mirrors. Two FBG sensors have same temperature coefficient and one of FBGs is coated by polyamide resin film as
moisture sensing material. This system is insensitive to temperature changes and the output power of the system is only
dependent on the moisture level to be monitored. The operation principle of the system is introduced and the initial
experimental results are demonstrated.