Both hardware and software are optimized simultaneously to improve the bus throughput of node computer in cluster computing network. A cost effective optical interconnection ring network is established using off-the-shelf PCs with windows operating system. A network adapter card ONIC is developed. Using ETDM and field program technique, the 1511 bandwidth of the 32bit

Piezo-electronic transducer is used in combination with mechanical scanning devices to improve measurement accuracy in a distributed polarization coupling detection system. For mechanical scanning range of 150mm with 200nm resolution, the measurement error of polarization-coupling intensity can be improved from 38% to 2% in combination with a 20-nm resolution piezo-electronic transducer.

White light interferometry has been adopted to measure distributed polarization coupling in high-birefringence waveguides. Since the coupling mode is weak compared to the exciting mode, the contrastratio of the interferogram is very low. This will increase the difficulty of direct detection of the polarization coupling intensity. By rotating the angle between the polarization eigenmodes and the principal axis of the linear polarizer from 45˚ to 85˚, the contrast ratio of the interferogram can be improved more than 10 times. As a result, the measurement sensitivity can be improved more than 100 times.

White light interferometry has been adopted to measure the distributed polarization coupling in high bireffingence thers A supoduminescent diode is adopted as the optical source in the white light interierometer To enlarge the reasorement range, the light beam in the scanning arm of the Micbelson interferometer is reflected three limes. Thus descanning range of the interferometer is doubled The full-width half-maximum spectrum of the SLD is 50nm, and cesenal wavelength is 1300mm. If the modal birefdngence of the I-IBF is 5

In this paper, white light interferometry has been used to measure the distributed polarization coupling in high birefringence fibres. Detailed theoretical analysis of the measurement accuracy of the testing system is presented. The main part is a Michelson interferometer with a scanning arm driven by a stepping motor. The minimum polarization coupling intensity detectable by this system is -77dB. The maximum fibre length that can be tested under this design is more than 1km, and the spatial resolution is better than 50mm. The influence of the opto-electro-mechanical devices on measurement accuracy has been analysed in order to improve the performance-to-cost ratio. This testing system can also be used in coherence division multiplexing optical fibre sensors.