| The rapid growth of optical fiber communication networks has created a large demand for many optical components, including optical switches. Fiber optical switches are used to reconfigure the network and /or increase its reliability. Low cost optical components are particularly important for fiber based local area networks. Recently, there has been a growing interest in applying the MEMS (Micro-Electro-Mechanical Systems) technology to improve the performances and reduce the size, weight, and cost of opto-mechanical switches. More importantly, the MEMS technology allows the monolithic manufacture of large matrix switches on a single chip. These optical matrix switches are the key missing components for dynamically reconfigurable DWDM (Dense Wavelength-Division Multiplexing) network.MEMS optical switch for optical communication is fabrication by silicon surface micromachining technology. Surface micromachining technique, based on the standard CMOS processes, in the other hand, offers greater flexibility for realizing free-space optical systems on a single chip.A fully micromachined multi-mode fiber optic bypass switch which is small, fast, and low power when compared to commercial bypass switches, has been designed.The magnetic actuation method has gained more and more attention in the field of MEMS. We have tried to use electrostatic to drive mirrors for switches. However, the electrostatic operation required large operation voltage. On the other hand, the magnetic operation is expected to realize self-latching optical switches, which hold on/off-state without power consumption. Magnetic actuation has been an excellent candidate for applications that require large deflection of actuators because of the well-known advantages over electrostatic, thermal, or piezoelectric actuation methods. Besides the simple control and relatively larger force by increasing the dimensions, one of the most important reasons for this is that the basic elements of the microactuators can be fabricated with IC-compatible micromachining technology, such as electroplating of Ni-Fe alloy, a soft magnetic material, and structuring of plane and three-dimensional coils by resist micromoulding and electroplating. Further, permanent magnets can also be fabricated with micromachining technology.Switching operation is provided by electrical currents in windings under the cantilever. Some key features are summarized as follows: (1) a self-latching system with electromagnetic force has been developed. (2) low energy consumption during switching ( switching current -100mA), low voltage operation (2-5V). (3) the realization of high quality mirrors together with a self-positioning system for the optical fibers. Thus, very low insertion loss can be obtained without expensive handling for alignment. (4) self-aligned vertical mirrors and V-grooves were simultaneously obtained.The performance of this thesis is as following:Firstly, outlined on optical switch and the MEMS technology. Market research on optical switch was carried through. Next, the technology of MEMS, the application of MEMS on opticcommunication was briefly introduced. Then, the status quo of MEMS optic switch was summarized, the existent problem was brought forward, the common drive mode was put forward. Finally, the purpose and method of this paper was presented.Secondly, the structure and the parameters of the optical switch were designed and modeled. The magnetic-cantilever optical switch was established according to the nonlinear of electromagnetic and the linear stress of the cantilever structure. Then, according to the established structure, the parameters of the optical switch were modeled and optimized. The thickness, roughness, verticalness of the mirror was analyzed and designed. Finally, the rectangular magnetic material was selected for the electromagnetThirdly, the parameters were optimized by ANSYS software and the performance of the optical switch was analyzed. The structure and magnetic coupling field was processed by ANSYS software. Next, th...
|
PDF Full Text Request