Design And Research Of Silicon Optical Switch Based On Mach-Zehnder Interferometer

With the much stricter requirements of capacity and speed of communication system,communication technology has achieved continuous development.Meanwhile,optical communication system flourishes as it has wider bandwidth,faster speed,lower loss and smaller crosstalk compared with traditional telecommunication system.And optical switch is playing a key role in the massive photonic switching systems of optical communication systems and networks.MEMS optical switch is widely used in the market currently.However,it appears that it cannot meet the demands of optical communication networks as its switching time is around the order of millisecond.Meanwhile,high-performance optical switches based on LiNbO3 and InP have drawn great attention in different universities and companies.While their price of materials and manufacturing costs are two main obstacles for their massive application in commercial markets.To balance high performance,low cost and massive production,optical switches based on silicon have shown great potential.This paper designs an optical switch based on Mach-Zehnder interferometer and SOI wafer.The active part of the optical switch is a phase shifter and it has a structure of rib waveguide.An FDTD simulation is carried on in order to optimize the structure of rib waveguide.We have designed and finally fabricated an optical switch which can meet most requirements in current optical communication systems.The experimental results show this optical switch has an extinction ratio of 21.8 dB at a wavelength of 1546 nm.The voltage demanded for switching is around 0.95 V and total power consumption is about 4.27 mW.For maintaining an extinction ratio of 20 dB,the applied voltage should be properly managed with a variation of less than 10.5 mV.Its switching time is in the order of nanosecond.The manufacturing of this optical switch is compatible with CMOS technology.As the minimum precision of submicron technology which is adopted in lithography is less than 100 nm and progresses towards 10 nm,it is much more superior than the demands of manufacturing such an optical switch.Many domestic companies and research laboratories are qualified for production and our optical switch was finally successfully manufactured by Microelectronics of the Chinese Academy of Sciences.The length of phase shifter in our optical switch is 500 ?m.As a result,the size of our device is quite small.So it has an advantage over electro-optic switches base on MZI which has a phase shifter in the order of millimeter and MEMS optical switches in the term of application of chip integration.This paper has successfully designed and manufactured a silicon electro-optic switch based on MZI.And in terms of its performance,manufacturing cost and possibility for integration,we have got some satisfactory results and the optical switch has no obvious defects.