Stuctural Desigh Of Surface Plasmon Lasers Based On One-dimension PhC Nanobeam Cavity

In the era of optical information,the development of faster information technology requires fast calculation and larger data volume.The optical interconnection technology as one of the solutions of the future information technology has a large digital capacity bandwidth and fast signal processing.But due to the existence of the diffraction limit,its size is difficult to further reduce.Surface plasmon has the characteristics of local enhancement in the near field,and its distribution depth can be less than the order of wavelength,which can break through the diffraction limit of light,and then achieve laser emission at a deep sub-wavelength or even nanometer scale,which is helpful to design and manufacture optoelectronic integrated devices.The ultra-small volume characteristics of surface plasma lasers provide the possibility of breaking the diffraction limit and further reducing the size of the laser.The paper designs a surface plasmon nano laser coupling cavity structure based on 1D taper Photonic Crystal(Ph C)to form a dual-cavity coupling and the lasing light directed output con Fig.uration,then realizing the structural design of a new plasmon laser.The novel coupling cavity structure not only has a higher Q factor of the laser cavity(the two couplers resonate simultaneously),but also achieves a high directional coupling output efficiency of the laser,which greatly improves the laser performance and output beam quality.The coupling cavity structure provides a new idea and method for practical laser source design for the next generation of Si-based photonic integration or hybrid photonic integration chips.The main study contents and study results of this article are as follows:(1)First we design a surface plasmon square cavity,we use FDTD Solutions software to model and perform simulation calculations,and analyze the effect of the resonant cavity size on the resonant wavelength.The size of the resonant cavity at the desired wavelength is 500 nm,the corresponding Q factor is about 33 and the Purcell factor is about 24.(2)We study the coupling output characteristics of the surface plasmon resonant cavity,so we design three kinds of waveguide coupling cavities,calculate and analyze the influence of their structural parameters on the characteristics of the coupling cavities.In order to obtain a device structure with high Q and high waveguidecoupling output,we optimize the structural parameters of the coupling cavities.The results show that the Ph C nanobeam can effectively enhance the characteristics of the surface plasmon resonator,and the taper Ph C coupling cavity has more obvious advantages.It is possible to achieve a Q factor of 385,a Purcell factor of 42,and a waveguide coupling efficiency of 78%.(3)Using the steady-state rate equation and the modulation bandwidth formula,we theoretically analyze the performance of the three waveguide coupling cavities and calculate the relationship between their output power and input current and the 3d B modulation bandwidth characteristics at different pumping rates.The results show that Ph C nanobeam can effectively increase the output power and modulation bandwidth of the surface plasmon resonator,and the taper Ph C coupling cavity has more obvious advantages.The output power of the taper Ph C coupling cavity is 50μW at a input current of 100μA.The modulation bandwidth under 1 time and 10 times threshold pumping rate are 5GHz and 18 GHz,respectively,it can be used for on-chip light sources.