The variable color LED optical source comprises first, second, and third
LEDs, each disposed to generate a linearly polarized optical signal; a
first beam splitter cube that is optically coupled to the first and
second LEDs; a first half-wave plate that is optically coupled to the
first beam splitter cube so that it is capable of rotating the
polarization orientation of an optical signal emitted from the first beam
splitter cube; a second half-wave plate that is optically coupled to the
third LED so that it is capable of rotating the polarization orientation
of the third optical signal; and a second beam splitter cube that is
optically coupled to the first and second half-wave plates so that the
second beam splitter cube is capable of emitting a fourth optical signal.