Study Of Optical Waveguide Devices Based On Magnetooptic Nonreciprocal Effect

With the rapid development of the optical communication technology,the constantly improving optical fiber communications system of the next generation drives the growing need of the industry. Small,functional,component-based development is a trend of the optical communication devices,and magneto-optical waveguide devices based on integrated optics have the characteristic of nonreciprocity as well as the advantage of low cost,small size,small losses and high mechanical stability,which is of great application value to optical information processing systems such as today's growing optical communications industry.As one of the most basic nonreciprocal devices——magneto-optical isolator is currently the most widely used and studied non-reciprocal device.Under the current magneto-optical waveguide isolators have been reported,according to the the different principles,the isolators can be divided into three main kinds:(1)Mode Conversion,reciprocal and nonreciprocal mode converters are both needed,the control of external magnetic field is complex,exact matched phase between TE mode and TM mode is needed,and the production tolerance is small,therefore,the devices based on TE-TM Mode Conversion have not demonstrated the practical application of good value;(2)Nonreciprocal loss (NRL),these devices must use the material of MQW and it is difficult to realize;(3)Nonreciprocal Phase Shift(NPS),exact matched phase and complex control of external magnetic field are not needed for this kind of devices,and waveguide structures have many other advantages such as flexible design,simple production process and more practical value.At present,research on magneto-optical devices based on NPS type focuses on the traditional theoretical analysis and the experiment research of the isolator of TM mode,this paper's research is mainly about the design of structures of magnetic waveguide devices based on non-reciprocal phase shift and the fabrication of magnetoopic wavegnide.In this paper,firstly,there is a theoretical research about the polarization characteristic of optical waveguide devices based on magnetooptic nonreciprocal effect.A highly effective polarization independent magneto-optical waveguide structure and its application are proposed.With the help of the method of finite difference,the theoretical analyze indicates that these polarization independent magneto-optical waveguide structures has a biggish NPS of about 2.5×10^-3μm^-1both for TE mode and TM mode,these structures can be used to design optical isolators and circulators and so on. Secondly,a simple and novel structure of polarization independent magneto-optical waveguide Isolator of MZI-type is proposed,this waveguide isolator has a NPS of about 2.0×10^-3μm^-1both for TE mode and TM mode with the clever use of a push-pull effect of nonreciprocity,and this isolator is easy to fabricate.Thirdly,the nonreciprocal filtering effect and application of the magnetooptic waveguide grating are researched,the spectrum characteristics of the magnetooptic grating are simulated by the software of BEAMPROP(Grating mode),the center-wavelength of the forward transmitted beam has a offset of 0.8nm to the backward transmitted beam.This feature can be used in optical isolator,optical combiner,as well as OADM.This magneto-optical grating structure is simple, which can be produced easily and integrated with other optoelectronic devices.This paper also explored the production processes of magneto-optical waveguides using the method of sputtering technology,the production processes we choose is:sputtering-annealing-lithographycorrosion-polishing-light passing experiment.By observing the surfaces of films under different conditions,we choose the most suitable condition:Sputtering pressure 0.5 pa,sputtering power 100 w, corrosion liquid H₂O/HCl(35.5%)=1/1.we have observed a marked plate image of the magnetooptical waveguide in the light passing experiment.In addition,the bonding programme which is used to fabricate magnetooptic waveguide is also discussed.