A polarization-mode dispersion(PMD) measurement system using a pair of polarization-state generators(PSGs) is demonstrated.Based on the saturation characteristics of magneto-optic rotators,the PSG can be digitally controlled,ensuring high-speed and highly repeatable generation of five distinct polarization states.Thus,the PSG can make full use of the advantage of the Mueller matrix method of PMD measurement.The experimental result shows that the system has good measurement repeatability and potential for field testing.
Irradiated by infrared laser, the surface reducibility and adsorbability of Cu-Cr complex could be improved, owing to the interaction of photo-fragmentation and laser texturing. Analyzed by the binding energy spectra and the auger spectra, the valence states of chromium ion and copper ion were+3 and+1 after radiation respectively, which still had the reducibility to release electrons. In contrast with the near-infrared(NIR)1 064 nm and mid-infrared(MIR) 10 600 nm laser at the same average output power of 15 W, the reduced metal percentage in the Cu-Cr complex was obviously distinguished at the depth from nanometer to micron. After chemical plating, the average coating thickness and mean-square deviation of the NIR sample were 11.61 μm and 0.30 for copper layer, and 2.69 μm and 0.08 for nickel layer. The results were much better than those of the MIR sample.
