Integrated optics asymmetric march-zehnder high-voltage sensors

• Main Author: Huang, Lisheng
• Format: Others
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/4857

Two types of integrated optics Mach-Zehnder (IMZ) interferometers, the striploaded IMZ and the domain-inverted IMZ, to be used for high-voltage measurements, have been investigated in this thesis. The devices are designed to have an asymmetry between their two branches so that the electro-optic responses in two branches are different when immersed in equivalent electric fields. The intensity of the output light reflects the strength of the electric field in which a device is immersed. In the strip-loaded IMZ the asymmetry is achieved by loading a T2i0 film onto one of the two branches, while in the domain-inverted IMZ the asymmetry is realized by inverting the spontaneous polarization in one of the branches. The operating principles, and the designs of the devices, are presented. The mechanism for domain inversion is also studied, and a defect process is proposed for the Ti-induced domain inversio in the c side of L.3iNbO The devices have been fabricated using the Ti-indiffusion method. The lithium out-diffusion, associated with the fabrication, is also discussed, and a pre-out-diffusion method is proposed to resolve the associated surface waveguiding problem. The test results of both device types are given, in particular, the measurements of the basic device parameters, i.e., the half-wave voltage, the intrinsic phase, and the on/off ratio. The results of stability tests and impulse tests are also presented. Also, for the first time in our laboratory, the annealed proton-exchange method has been used to fabricate optical waveguides. === Applied Science, Faculty of === Electrical and Computer Engineering, Department of === Graduate