| With the development of next-generation electronic communication technology,data traffic for transmitting information is increasing,which is driving the development of optical communication technology towards higher speed,higher capacity and lower power consumption.Distributed feedback(DFB)lasers and vertical cavity surface emitting lasers(VCSELs)have dominated the optical communication market,but there are still their own shortcomings.Photonic crystal surface-emitting lasers(PCSELs)are of great significance as key device research in this field and have a wide range of applications in several fields.In this paper,a gallium nitride(Ga N)-based photonic crystal surface-emitting blue laser is designed based on the photonic confinement properties and photonic localization properties of photonic crystals.The parameters are optimized using the time-domain finite-difference method,and the laser performance is improved by using heterogeneous structures.Then,based on the classical rate equation,the expressions of the core parameters of the laser are derived,and the basic and high-speed performance of the designed laser are analyzed and compared with other types of lasers.The specific work is as follows:(1)Based on the principle of photonic crystal forbidden band,photonic localization and band-edge excitation,a heterogeneous structure of photonic crystal surface emission laser is designed.The effects of air hole radius,etching depth,upper layer p-Ga N thickness,lower layer n-Ga N thickness and lattice constant of photonic crystal on the resonant wavelength,quality factor and limiting factor of PCSELs resonant cavity are investigated by using the time-domain finite difference method in the infinite area case.Based on this,a heterogeneous structure is used to divide the photonic crystal layers into core,transition and cladding layers,and the effects of air hole radius and number of layers of different layers on the resonant wavelength and quality factor of the resonant cavities of PCSELs are investigated.(2)Based on the classical rate equation model,the expressions for the threshold current,3-d B modulation bandwidth and output power of the PCSELs are derived.The fundamental performance and modulation bandwidth performance of the designed Ga N-based PCSELs are analyzed,and the threshold current is 10.94 m A,the maximum 3-d B modulation bandwidth is 45.71 GHz,and the minimum data transmission energy consumption is 1.9 n J/bit under the studied laser structure parameters,as calculated by simulation.(3)Other lasers such as Ga As-based double lattice surface emission lasers,high-speed ultra-compact buried heterostructure photonic crystal lasers and optical crystal nanobeam lasers are listed to compare the advantages and disadvantages between them and show the advantages and necessity of the designed PCSELs.Then the number of quantum well layers is increased and the laser is further investigated to obtain better performance parameters.Finally,the trend and relationship between the calculated and simulated values of the threshold current are investigated by changing a single parameter through the controlled variable method.The PCSELs designed in this paper have relatively low threshold currents and large modulation bandwidths with practical manufacturing value.Through the derivation of equations and analysis of high-speed modulation performance,a set of simulation calculation and analysis of the fundamental performance and dynamic modulation performance of semiconductor lasers is finally developed,which provides a theoretical basis and design guidance for the design of PCSELs with excellent characteristics and high-speed modulation features. |
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