Fluctuational crosstalk in Ti:LiNbO/sub 3/ directional coupler switches

It has been found that the fluctuations in the Ti concentration along waveguides of Ti:LiNbO/sub 3/ directional coupler switches degrade the switch extinction ratio and introduce an unwanted crosstalk between both channels. We discuss analytically the effect of effective optical index fluctuations on the transfer matrix of the optical switch. We demonstrate the sensitivity of the mismatch to the statistics of the fluctuations of the Ti concentration.<
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