Study Of A Single-crystal Erbium Silicate Near-infrared Laser With Vertical Emission And Fluorescence Upconversion

The invention of the transistor in the middle of the 20th century ushered in the semiconductor industry,the information age,and a time of fast global progress.Meanwhile,the microelectronic chips based on silicon materials are developing towards highly integrated and miniaturization at a high speed,rapidly becoming an important part of current human life.At the same time,issues like the difficulty of processing technology to fulfill device requirements have grown in importance.These issues include interconnect delay effects,steadily rising energy consumption caused by high integration,and others.The combination of photons and electrons in silicon-based optoelectronics was created to address these issues.Silicon based optoelectronics has the mature technical foundation of microelectronics,but also has the advantages of photon crosstalk,large bandwidth,high speed,in addition,silicon based optoelectronics effectively circumvent the limitations of both.As a result,silicon-based optoelectronics has gained popularity as a research area,and several useful devices,including modulators and detectors,have been created with mature fabrication technologies.The cornerstone of the big data age and the primary device in the post-Moore era is silicon-based optoelectronics.Silicon materials are not appropriate for the direct preparation of optoelectronic devices due to the poor luminescence efficiency of silicon.Erbium-doped materials are frequently employed in the various of silicon-based light sources because of their effective luminescence in the communication band.Due of this,several recent investigations on erbium silicate compounds have garnered a lot of interest.Erbium silicate compounds have overcome the restriction of solid solubility,raised the concentration of erbium ions by three orders of magnitude,and further enhanced fluorescence efficiency.It opens up new opportunities for silicon-based light sources with small-sizes and high gains.Numerous optoelectronic devices,such as thermometers,light-emitting diodes,and photodetectors,were created.However,erbium silicate material cannot be used to directly manufacture optoelectronic devices because of its insulating characteristics.As a result,it is crucial that energy is transferred effectively between the erbium silicate material and the conductor semiconductor.In light of this,this thesis prepares erbium silicate material using the chemical vapor deposition method and increases the ytterbium ion to boost its fluorescence efficiency.The material’s single crystal characteristics were clarified by a variety of characterizations,and its steady-state and transient spectra were fully tested using a self-built visible to near-infrared spectroscopy test system to verify its performance.On this basis,the near infrared laser combined with distributed Bragg reflection resonator（DBR）was successfully fabricated and analyzed in detail.The difficult-to-realize up-conversion fluorescence emission in the semiconductor under the excitation of the infrared continuous laser is achieved on this premise by combining the silicate material with the semiconductor material to realize the energy transfer between the two.The following is a summary of the major representative research findings:1.Chemical vapor deposition was used to controllably create silicate single-crystal nanosheets that were with erbium and ytterbium and had a high cation ion concentration.Scanning electron microscopy,X-ray diffraction,transmission electron microscopy,and other methods of morphological and structural characterization revealed that the chemical formula of erbium-ytterbium silicate single-crystal nanosheets is（Er/Yb）₃（Si O₄）₂Cl,in which Er ions are reaches a maximum concentration of 5×10²²cm^-3.The material has stable luminescence in both the visible and near-infrared bands,which are derived from the upconversion fluorescence and metastable state of Er ions ⁴I_13/2 energy level,respectively,according to spectroscopic characterization performed by a self-built visible-infrared steady-state transient spectroscopy test system.Among them,the near-infrared fluorescence lifetime at 1.53μm is as long as 2.3 ms.Its lifetime density product is expected to be 1.15×10¹⁸ s/cm³.This value,which is the maximum value of all lifetime concentration products reported so far,offers a high-quality material base for the realization of optical amplifiers and lasers with high gain.2.Based on the high quality Erbium-ytterbium silicate nanosheet,a vertical emission laser in the near-infrared communication band（1500 nm）has been successfully realized by properly designing a Bragg reflective microcavity.The dielectric layer with the proper materials and thickness was deposited,and the Erbium ytterbium silicate nanosheet was embedded into the upper and lower Bragg mirror structure to form the DBR resonator.This was done through the selection of alternating refractive index materials and thickness calculation of DBR microcavity.A pulse of light with a wavelength of 976 nm,pulse width of100 fs,half-height width of 10.5 nm,and repetition rate of 1 KHz was used to stimulate the DBR resonator.We obtain a series of maser modes with typical F-P cavity modes.The vertical surface emitting laser has a threshold as low as 20J/cm²,and its Q factor is around 2000.This study offers a fresh approach for the creation of silicon-based small-scale coherent light sources.3.The up-conversion fluorescence of CdSe/ZnS quantum dots is accomplished based on the composite film structure of high-quality erbium ytterbium silicate single crystal nanosheets and CdSe/ZnS quantum dots.Dry transfer was used to create erbium-ytterbium silicate composite films covered with CdSe/ZnS quantum dots.By comparing time-resolved spectra at wavelengths below and above the quantum dot band gap value,976 nm and 488 nm,respectively,it was discovered that silicon had significant energy transfer between the silicate nanosheets and quantum dots.Its energy transfer efficiency is at 50.2%and it is a member of the F?rster energy transfer.An experimental foundation for visible-to-infrared optoelectronic devices is provided by this work,which accomplishes continuous near-infrared laser stimulation of CdSe upconversion fluorescence.