In order to eliminate the loss of the conventional RCD(resistor, capacitor and diode),a new lossless snubber using magnetism coupling is introduced.

The paper makes a complete theory analysis for the operation of the LCD nondissipitive snubber used in the forward-reverse-combined converter.

The results indicated that after the Nd,Cr:GSGG crystal was annealed in the oxidation atmosphere,the absorption spectrum exist two absorption bands near 1μm due to some Cr~(4+) ions in the crystal,which are called 1μm absorption loss.

Titanium oxide and silicon dioxide were used as thinfilm materials and deposition parameters were optimized to minimize the absorption loss,so there could be effective reflection reducing and protection for fluorinated magnesium substrates.

Absorption loss due to high harmonics of C-H vibrations, the primary loss factor in PMMA POF, was analyzed and calculated.

A quarter-wave conventional film system was adopted to analyze the main effect of the distribution of electric field intensity,absorption loss and the scattering loss on the properties of 193 nm HR mirror.

According to the absorption properties of erbium-doped optical fiber, there would appear a sharp absorption loss, which brought more difficulties to the actual measurement of slow light and its application in communications.

In order to reduce the pollution, which the electromagnetic wave being reflected back into air will pollute again the electromagnetic environment, in this paper, the double gradient model for shielding functionally gradient materials (SFGM) was put forward to realize low reflection loss and high absorption loss for electromagnetic wave.