An all fiber acousto optical tunable band pass filter with a sandwich fiber structure was designed to overcome the band notch filter problem of fiber acousto optical filters based on single mode fibers.

From the angle of aesthetical psychology, the reason was analyzed why three-segment in design is so popular among the public,especially among master art-designers,and the methodology and technique in applying the idea in plane and product-plastic design was also discussed.

To confront with the opportunities and challenges of "Lewis interval",higher vocational education should construct new "three-segment" model of combination of working with learning,every segment operates independently as well as link organically to form harmonious symbiosis.