Interferometric activated X switch: IAX

High-speed phase-linear switching with low crosstalk is accomplished by using balanced bridge interferometric switches with electrooptic tunable X couplers. The devices are fabricated by titanium indiffusion into X-cut, Y-propagating LiNbO/sub 3/. Lumped-element and traveling-wave electrodes of aluminum, gold, and indium-tin oxide are investigated. Devices with a 3-dB bandwidth of 6.5 GHz using coplanar traveling-wave electrodes with a switching voltage of 7.0 V, an insertion loss of 4 dB, and -35 dB extinction ratio are realized for lambda =1.3 mu m. Improvements in DC drift stability due to electrodes and buffer layers of indium-tin oxide are reported.<
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