Technical Specification of Optical Fibre.

hi,

can anybody help me to understand following few terms of optical fibre used in its technical specification:

1. trapping efficiency, round fibers

2. trapping efficiency, square fibers

I have understood that optical trap is able to hold a small particle at its centre. It is able to detect very small displacements and find uses in physics and biology. But, trapping efficiency of round fibers is only 3.44%; and that of square fibers is only 4.4%. What does this very small efficiency indicates?

3. No. of H atoms per cc (core)

4. No. of C atoms per cc (core)

5. No. of electrons per cc (core)

6. Radiation length

7. Vacuum compatibility

Regards,

sks