  The optical properties of optimally-doped Bi_2Sr_2CaCu_2O_{8+\delta} (Bi2212)
have been measured normal to the edge planes [ac plane, bc plane, and
(1\bar{1}0) plane], for light polarized parallel to nodal and anti-nodal (gap)
directions, respectively. While the superfluid contribution can be obtained
from the optical conductivities in the (1\bar{1}0)-plane, it is unobservable in
the ac and bc-planes. This apparent asymmetry implies that the edge region of
high-T_c cuprates is unusual and further supports a d-wave symmetry of the
superconducting order parameter.
