44 2 the upconverted optical signals u03bb oe1d u03bb oe4d are combined in the combiner 62 prior to transmission the interleaving of the electrical frequencies being upconverted allows for the use of optical filters 58 with either single or double sideband modulators to remove any unwanted sidebands or carrier wavelengths from the optical signals u03bb oe1d u03bb oe4d transmitters 12 of the present invention can also be used to modulate data onto the lightwave carrier wavelength in addition to upconverting electrical frequency onto the lightwave in the present invention transmitters 12 configured to provide multiple optical signals can be further configured to impart opposite polarization to pairs of optical signals being generated by upconverting the electrical signals for example the optical combiner 62 in embodiments such as those shown in fig1 and 16 can be a polarizing component such as a polarizing beam splitter combiner the orthogonal polarization of adjacent signals will reduce or eliminate nonlinear interaction between the signals thereby providing for more closely spaced signal wavelengths and high power signals alternatively as shown in fig1 a separate polarizing element 74 can be included in the combiner 62 an embodiment of the polarizing element 74 can includes two oppositely configured polarizing beam splitters 76 connected in series by two parallel paths 78 that produce a differential travel time between the splitters 76 the first beam splitter 76 splits the optical signal into two equal amplitude polarization components the second beam splitter 76 is used to recombine the two polarization components the time differential introduced by the parallel paths 78 can be established and or controlled to introduce differences in the polarization of the channels for example optical signals having sufficiently narrow bandwidths can be introduced.