Applied Research On Poled Polymer Electro-Optic Switches

Since the ancient China used the beacon towers to impart information, the developing direction of modern optical communications has been bred. With the coming out of laser devices, fiber with low loss and optical detector with low noise, optical communications are going to maturity length by length. Especially, the EDFA that was invented in late 20th century has saved the process of EO-OE conversion in the optical communication, and then the new optical network which based on the technology of WDM was born.The development of optical network includes two parts: one part is that the optical network gains a wider ground in the aspect of transmission network, and covers the connection network, that is what we called'fiber to house'; the other is that it reduces the EO-OE conversion in the process of information conversion, makes a good use of the high light speed and finishes the optical conversion and access directly, that is to say, achieves the goal of optical network. Optical network must depend on super high-rate and super large-capacity bit's transmission, the fast conversion and share of the network information, the fast-rate and economical rout choice. All of these are relevant to the core apparatus of optical network.This paper mainly studies the upstart of the optical switch family—polarized polymer Electro-Optical (E-O) switch, its main characteristics include the following: high electro-optical (E-O) coefficient, excellent filming characteristic, high shaping trait, good processing speciality and outstanding underlay compatibility. Especially, the breakthrough headway in the main aspects of optical loss, changeable refractive index, heat stability and the huge advantage in the aspects of high-speed E-O switch and modulator have made it the basic material that has a good foreground with low cost. Because of the super high on-off speed, polymer E-O switch has become the international research foreland and showed a wide application foreland in the new generation of optical network and the RoF system. High-speed polymer digital optical switch (DOS) is a research foreland of recent years, compared with the inorganic E-O switch,polymer E-O switch has obvious advantage in the aspects of the switch speed and preparation process, moreover, it has strong ability to repel electromagnetism molestationf, and the loss and cost are low. Polymer optical materials have a wide variety, so some weakness can be improved and optimized through molecule devise.The purpose of the task is to collocate polarized polymer materials with high E-O coefficient, to test the E-O coefficient and to study the preparation process of polarized polymer E-O switch. In this paper, we introduce the traits and researches of some kinds of optical switches, put research point on the basic theory of polarized polymer E-O switch, and then, we use sol and gel technology to adulterate chromophore DR-1 to SiO₂, and collocate the organic/inorganic E-O materials and make some exploratory research.This paper inherits the former experience, but does not only pursue high E-O coefficient, we pay more attention on the heat stability, depreciation, dynam stability of the materials and the stability of the tropism of the chromophore. Besides, we study the smoothness and the thickness of the film.In this paper, we mainly use the simple reflection technique to test the E-O coefficient of the materials, and use the ellipsometer WVASE32 to test the refractive index and the thickness of the film, and use the atomic force microscope DI3100 to test the smoothness of the film. In the end, we test the capability of the waveguide apparatus. These testings have provided authentic data for the further research of E-O switch.In the research process of the waveguide technics, we work on the choice and cleanout of the underlay, sputtering , photolithography, RIE and so on.We get the adulteration of organic and inorganic E-O materials through sol and gel technology and the optimal concentration ratio and the heat treatment condition. The E-O coefficient of the adulteration r3 3 can reach 20pm/V and hold the line for long time under normal temperature, and this can meet the need of making the E-O switch.In the aspect of testing the E-O coefficient, after balancing many testingmethods, we at last choose the reflection technique brought about by Teng and Man. We set up the testing equipments and adjust the testing system by measuring the E-O coefficient of the GaAs crystalloid; this has improved the creditability of our datum.In the design of the waveguide, we coat the E-O material on the core of the chip, make it modulation layer, and only reserve the E-O material in the part of modulation, etch the other parts out, and make the core ridge waveguide. In this way, in the area of non-modulation, the light diffuses though the core medium, and in the area of modulation, because the refractive ratio of the E-O material is higher than that of the core layer, the light enters the E-O layer and then is modulated, this has accounted for the thin film and the high dispersion loss.In the aspect of making the waveguide, on the premise of the designing conception, we use silicon dioxide as the underlay, and meanwhile, the silicon dioxide serving as the below envelop has simplified the experimental technics. Because the thickness of the E-O material is only 500nm, we sputter DR-1/Silica on the E-O material, and then choose PMMA+GMA as the buffer layer of the core,and have got favorable light access.