POLARIZATION SPLITTING IN LOSSY GAINY MQW DIRECTIONAL-COUPLERS/

We analyze polarization splitting of light in directional-coupler pola rizers by using a transverse modal transmission-line representation. B ecause it is based on rigorous modal solutions, this approach provides very accurate results and can be applied to situations involving eith er lossy or gainy materials, By considering a polarizer in which multi quantum-well layers act as one of the two waveguides forming the coupl ing region, we find that maximum polarization discrimination is achiev ed at an optimal distance that is different from the polarization leng th predicted by conventional coupled-mode methods. We derive a novel c riterion for determining that optimal length, examine the effect of ma terial loss or gain, and obtain the far-held intensity of the light at the output of the coupler.