Research On Low Loss Semiconductor Nanolasers Based On Surface Plasmons

Miniaturization is an inevitable requirement for the development of laser technology and plays a key role in the integration of optical components.As a kind of deep sub-wavelength nanometer scale coherent light source with ultrafast dynamics,the plasmon laser is called the smallest laser in the world and is one of the most effective techniques for overcoming diffraction limit and miniaturization of lasers.Plasmon lasers can realize the optical interaction at the nanometer scale with unprecedented resolution and ultrafast physical dynamics,thus provides technical support for new scientific discoveries,and has broad applications in areas such as optical integration and sensitivity biological detection.However,at present,there are still two main problems in the research field of plasmon lasers: firstly,the imperfect high-quality metal film preparation theory and imperfect fabrication technology lead to extra metal losses which are too high,thus affecting the threshold performance of plasmon lasers;secondly,the threshold of plasmon lasers composed of inorganic or organic gain materials is still high.These two problems severely limit the practical application of plasmon lasers.In order to solve the above problems,the project "Research on Low Loss Semiconductor Nanolasers Based on Surface Plasmons " has carried out with theoretical analysis and experimental research in order to lay a solid foundation for the practical applications of plasmon lasers.The research results of this paper further enrich the theoretical system of plasmon lasers and provide technical reserves for plasmonic optical devices.This work has important application value in the field of nonlinear optics,super-resolution imaging,and subwavelength photonics integration.The main research contents of this work include:1.On the basis of previous studies,the characteristics of plasmon lasers are systematically studied in theory.The ultra-strong mode confinement characteristics of plasmon lasers are analyzed using finite element method.The spontaneous emission enhancement of the surface plasmon lasers and its influence on the laser behavior are discussed.The dynamic process of surface plasmon lasers is studied.The loss characteristics of plasmon lasers are studied.The above work provides theoretical guidances for preparation,experimental characterization and performance optimization of plasmon lasers.2.In order to reduce the cavity losses,the theory and technology of preparation of metal thin films are studied deeply.The growth processes of silver thin films under different deposition conditions are studied in order to perfect metal film growth theory.A simple and low-cost process is proposed to realize the epitaxial growth of silver thin films.Monocrystalline silver thin films with a large area of ultra-smooth surface are obtained,which are near the ideal state in terms of both dielectric property and surface roughness quality.The influence of metal thin films quality on the performance of Zn O nanowire plasmon lasers is verified by using monocrystalline silver films,template-stripped silver films,and general deposited silver films.The results show that the monocrystalline silver film can enhance the threshold performance of surface plasmon lasers.According to the experimental results,the analysis of cavity losses and material losses compensation is conducted.The results show that material losses are the main factor to limit the further reduction of laser threshold.3.From the perspective of material losses,by studying the optical gain material with high optical conversion efficiency,using organic-inorganic hybrid perovskite materials as the gain semiconductor is proposed to fully compensate the losses in the device,thus to realize low threshold plasmon lasers.High-quality monocrystalline CH3NH3 Pb I3 nanowires are prepared by low-cost low-temperature solution synthesis method.The prepared nanowires have good geometrical features and excellent optical properties.The plasmonic perovskite nanowire nanolasers are then fabricated.The results of optical characterization experiments show that the nanolasers can achieve low threshold lasing at room temperature,with the lowest threshold of 13.5 ?J cm-2,and have ultrafast lasing dynamics.The maximum operating temperature of the laser is up to 43.6 ?.