The Research And Manufacture Of Nanosecond All-fiber Magneto-optic Switch

With the continuous development of optical network,the demand of high-speed and reliability of optical switch is increased.Magneto-optic switch is expected to play an important role in all-optical network due to its high switching speed,operating at low voltages,featured as low insertion loss and intrinsic non-reciprocity.A new Magneto-optic switch is proposed and manufactured by the supporting of Science and Technology Project of Fujian Province.The experiment results show that the magneto-optic switch have the characteristic of high-speed.According to the component and reference function of all-fiber magneto-optic switch,this paper includes the following aspects.(1) Design and manufacture of light mutesThe light routes are the core of the magneto-optic switch,it decides the overall performance,cost and structure of magneto-optic switch.The design of light routes is mainly basing on Faraday effect of magneto-optic material and the character of linear polarized light.All-fiber magneto-optic switch comprise Polarization Beam Splitter, Polarization Beam Combiner,and magneto-optic material and so on.The design of light routes is basing on the national patent "All-fiber magneto-optic switch" which belongs to our laboratory.(2) Design and manufacture of circuitBy controlling the current plus to drive magnetic circuit,the magneto-optic material GSF(or GMF) is magnetized,then the linear polarized light passing through it will be rotated.The circuit and magnetic circuit is the key to the switching time.In this paper,three kinds of drive circuit are designed.MC33886 controlled by AT89S52 is used to generate bidirectional current plus.The other two kinds of circuit are similar. DE150 and FMMT415 are used to produce plus whose rising time stay on nanosecond. All three kinds of circuit are analyzed and optimized.(3) Design and manufacture of magnetic circuit Magnetic circuit is used to drive Faraday rotator directly,its structure is crucial to the switching time of magneto-optic.Three kinds of magnetic circuit are designed and analyzed.After taking various situations into account,the solenoid type is chose. The dimension of solenoid decides the whole structure of magneto-optic switch.The structure of solenoid is analyzed and designed,and the magnetic field and inductance are also calculated and tested.