Study On Traveling-wave Electrode And Test Analysis Of Electro-optic Modulator

Electro-optic modulator is the key component of fiber transmission network and high speed optic-electro information management system. The microwave signal loads on the optical signal with the modulator, which could use the wideband superiority of the fiber communication. With the rapid development of fiber communication, the modulators are paid more and more attentions by researchers. At present most commercial electro-optic modulators are prepared by LiNbO3. Compared with inorganic materials, polymer electro-optic materials have a lot of merit. But most of the polymer electro-optic modulators are still researched in the laboratory due to the bad thermal stability and high loss and so on. Now researchers are using hybrid materials to prepare the modulator which has good thermal stability. We use sol-gel technique to prepare organic/inorganic material with better thermal stability.Among all of the modulators, Mach-Zehnder modulator is widely used, Their structure is easily fabricated and used because it skillfully utilizes the optical interference effect and doesn't need polarizer and analyzer. Modulators are consisted of waveguide and electrode, The performance of the electro-optic modulator is decided by its electrode system while the part of waveguide has been prepared.The electrode system has been discussed, and the electrode was tested by vector network analyzer. Also the character of modulator was tested and analyzed , while the electrode was loaded on the waveguide.The history and the latest developments in electro-optic modulators have been introduced. The electro-optic materials and the structure we used in the modulator were also introduced in detail.The integral part, constituent structure, principle of work and performance indicator of traveling-wave electrode system were analyzed. With theoretical calculation and software simulation, we got the parameters of Microstrip line and prepared the stencil-plate. According to the electro-optic materials, the stencil-plate for coplanar waveguide was also improved.A great deal samples were prepared by semiconductor craft, and electrodes were also fabricated on lots of substrates. We also prepared some microwave probes, and build a platform for the test by the probes and fine-tuning system. The samples were test by vector network analyzer.At last, traveling-wave electrode was successfully fabricated on the waveguide, and the poled polymer electro-optic modulator has been tested and a good curve of modulation was also received. A tee bias network was used to adjust the liner operation point. From the results, half-wave voltage could be calculated. And the other parameters of samples were also tested.