Theoretical And Experimental Research On The Coupling Of 4×4 Integrated Optical Waveguide Switch

Our society is moving towards the information era nowadays, and technology of optical fiber communication is developing rapidly. Every node in transmission network needs to convert optics into electricity. In this process the electronic devices restrict the speed and bandwidth of information. The problem can be resolved by using all optical network,in which optical switch is the key device. Optical switch is chiefly used in OXC(Optical Cross Connection) system in optical network. It can fulfill many functions such as routing, selecting optical wavelength and OXC etc. Waveguide optical switch is one of the switches,which are of the best prospect. Compared with mechanical optical switches, it has the merits such as fast switch time(wide modulation band width),low coupling loss, high integrated level etc. In this paper we analyze the theory of 4×4 LiNbO3 waveguide optical switch matrix thoroughly, which is composed of directional couplers. Also the electrooptic modulation of LiNbO3 and the theory of rectangle waveguide transmission have been lucubrated. The coupling and encapsulation technology of the waveguide switch matrix has been researched emphatically.Starting with coupling theory of fiber and waveguide,we summarize the status and progress of the coupling single mode fiber to strip waveguide technique,and also we study the transmission modes in surface coupling. An improved "inversion－chip" coupling method is used in the Ti:LiNbO3 optical waveguide coupling experiments. Based on the anisotropic etching Si(100) theory, we improve the three-system etchant and determine the optimum fabrication technology. In the process of fabricating V-grooves, the devices for experiments are designed. Through a lot of experiments,we have successfully designed and fabricated the V-grooves. In order to realize precise matching between the Ti:LiNbO3 waveguide and fiber,we design experimental devices for packaging and finally fabricate the array of V-grooves and fiber. This paper studies the fabrication technology of the Ti:LiNbO3 waveguide devices in detail, such as photoengraving, sputtering and diffusion. Through experiments,the coupling of single mode fiber and waveguide switches has been researched thoroughly,and experimental devices have been designed.At the end of this paper, the results of fabricated optical switch matrix are given. The testing system is established. We test the fabricated optical switch to get the parameters such as insertion loss, and obtain stepped achievements.