A polarization splitting grating coupler (PSGC) connects an optical signal
from an optical element, such as a fiber, to an optoelectronic integrated
circuit. The PSGC separates a received optical signal into two orthogonal
polarizations and directs the two polarizations to separate waveguides on
an integrated circuit. Each of the two separated polarizations can then
be processed, as needed for a particular application, by the integrated
circuit. A PSGC can also operate in the reverse direction, and couple two
optical signals from an integrated circuit to two respective orthogonal
polarizations of one optical output signal sent off chip to an optical
fiber.