The different polish rate for different polish material cause dishing.

The influence of the pressure,polishing temperature,oxidant concentration and slurry flow rate on polishing rate was discussed.

The mechanism of W-CMP was analyzed,the slurry makes a dual function of chemical erosion and mechanical lapping,has an important influence on the polishing rate.

To reduce the roughness and keep agreeable polishing rate,different polishing processes were needed,the hardness of polishing pad and the particle diameter of silicon dioxide in slurry should be reduced gradually,and the pH of slurry should be kept at appropriate range.

The influence of concentration of rare-earth ions Er3+ and Yb3+ on gain and noise characteristics of Er3+/Yb3+ co-doped double-clad fiber amplifier is analyzed based on rate equation and light propagation equation.

Comments added to the small signal analysis of rate equations of semiconductro lasers;

Taking into account the energy transfer from Yb~(3+) to Er~(3+), the rate equations are given for Er~(3+) ions.

Deriving from the rate equationsmodel of fiberlasers,wegetthe explicitexpressions of outputpowers,slope-efficienciesand thresholdsof fiberlasers.