Then the morphology was observed by optical microscope and SEM. The grain size of austenite, the number of martensite in austenite grains and the spacing of the lath martensite were measured.

Dominant group, average spacing and average length of joints are carried out with statistical analysis using data measured from 837 outcrops in these two blocks.

The measured time delay responses are nearly linear with the wavelength spacing between optical carriers as well as the lengths of FDLs, which agrees well with the theoretical analysis.