Research On Q-value Enhancement Of Resonant Cavity With Resonant Optical Tunneling Effect

Optoelectronic devices are the basis of optical communication networks,and optical resonant cavities,as typical optical structures,are widely used in devices such as optical filters,buffers,and optical switches.The quality factor Q value is an important parameter to measure the performance of an optical resonant cavity,which represented the ability of a resonant cavity to store light energy,the pursuit of a higher Q value is one of the eternal themes of resonant cavity research.Additionally to performance,there are many types of optical resonant cavities and each has its structural characteristics.Therefore,for different application scenarios,exploring optical resonant cavities that meet actual needs can not only broaden the application field of optical resonant cavities,but also give full play to their respective advantages of the characteristics.Optical resonant cavity based on Resonant Optical Tunneling Effect(ROTE),compared with the classic Fabry-Perot cavity,Whispering Gallery Mode cavity,Photonic Crystal Microcavity and other resonant cavity structures,it has easy integration,high stability,simple process,low cost and other advantages,have certain potential application value in promotion and application.In the previous research work of this research group,the application of ROTE resonant cavity was initially explored,and it was found that it has a certain application potential in the field of biosensor,and the improvement of the quality factor Q value has become the key to its further promotion and development.To this end,this article has carried out a series of studies to improve the Q value of the ROTE resonant cavity.First of all,this article uses the transfer matrix method to construct a ROTE structural simulation model,analyzes the influence of different structural parameters on the Q value,and provides theoretical guidance for experimental debugging.Based on the simulation results,the silicon wafer with a low absorption coefficient was selected as the resonant cavity,and a preparation plan for the ROTE resonant cavity was designed.Based on the prepared ROTE Microcavity,a test platform was built to study the influence of the incident light polarization state,the thickness of the tunneling layer,the cavity length and the incident angle on its Q value.The experimental results show that the Q value of the ROTE resonant cavity is as high as 1.4 10~4,which is about 20 times higher than that of the ROTE cavity prepared before(Q value is about 650).In the experimental test,the experimental results obtained by adjusting the above four parameters are in line with the simulation trend within a certain range;but when the tunneling layer thickness and the incident angle continue to be increased,the measured signal resonance depth is too shallow,and the signal-to-noise ratio drops,cannot accurately measure its Q value.This article also briefly analyzes the reasons for the difference between the simulation model and the experimental results.As a method to improve the Q value of a resonant cavity,the ATS(Autler Townes Splitting)effect and the similar electromagnetically induced transparency effect can realize the slow light propagation of optical pulses.For the all-optical buffers,high-speed optical switches and other devices in optical communication technology R&D has great reference value.Analogous to the Whispering Gallery Mode resonator,this paper constructs a coupling structure based on dual ROTE cavities to realize the ATS effect.In addition,by adjusting the polarization state of the input port,a single ROTE resonant cavity is successfully used to achieve a similar electromagnetic induced transparency effect.Compared with the ROTE cavity under the same parameters,the Q value has been significantly improved.