Organic Polymer Quasicrystal Photonic Crystal Laser

The rapid development of information society mainly relies on various information technologies,such as network,software and artificial intelligence.Integrated circuit technology is one of the most important technologies.The carriers of integrated circuits are electrons.The coulomb force between the electrons makes the integrated circuit chip size small to a certain extent,which causes large energy loss and affects the performance of the device.While the interaction between photons is extremely weak.As a new carrier of information,compared with the electrons,photons also have the advantages of large capacity,high speed,more confidentiality and stronger anti-interference,reducing chip size meanwhile improving device performance and widely used in industries such as all-optical communications and other industries.Photonic crystal(PC)is a new material taking photons as carriers,which has been widely concerned and applied to various light-emitting devices and lasers,since the concept was first proposed.Photonic crystals inhibit the propagation of electromagnetic waves in the bandgap.When the frequency of spontaneous emission of the material overlaps with the band gap,spontaneous emission will be inhibited.Then the energy loss due to spontaneous emission is greatly reduced,the laser threshold is lowered.The single-mode output of the laser can be achieved by introducing defects in the structure.Unlike conventional periodic PCs,quasi-periodic photonic crystals(QPCs)display high rotational symmetry orders,which have excellent optical locality under low refractive index.Up to now,most of the laser gain media are inorganic sewith mature physical regulation.Comparing with inorganic semiconductor materials,miconductor materials organic materials have advantages in simple preparation process,tunable luminescence spectrum,available for large-area flexible display and so on.Therefore,organic semiconductor photonic crystal laser has gradually become a research hotspot.Combined quasicrystal structure with conjugated polymers with remarkable optoelectronic properties,we design and fabricate the optical pump laser and the electric pump laser based on conjugated polymer as luminescent materials and gain medium:1.Finite-difference time domain method is used to study theoretically the localization in single octagonal quasicrystals defect cavity and coupling properties of defect modes between two cavities with different spacing under the low refractive-index contrast.It is found that the patterns of modes don't change while the wavelength shift as movement of defect cavities position.If the defect possess the same rotational symmetry,the resonant frequencies of the defects are identical.Moreover,uncoupled modes exist in defect ca'vities when the field symmetry of defect modes is different from that of external exciting waves.A new resonant mode occurs excited by a bigger composite resonator with neighboring double defects due to the low index of the material.The simulation results lay a theoretical foundation for the design and fabrication of optical pumped organic laser,electric pumped organic laser and organic laser arrays.2.Optically pumped organic quasicrystal lasers based on the silver mirror-quasicrystal-silver mirror structureare is designed and optimized,the silver mirrors used as reflectors vertically.Quasicrystal structure is used to select mode horizontally and localize the mode in the defect.The film thickness can be controlled to select mode vertically and then light oscillates and amplifies in the microcavity and emits from the side of the thinner silver layer vertically.Lasing is observed at a wavelength of 605.4 nm with a narrow linewidth of 7 nm.Pumping threshold of the laser is 21.1?J/pulse.3.Optically pumped organic quasicrystal lasers based on the quasicrystal-multilayer mirrors structure is designed and optimized.Different from the above structure,multilayer mirrors is adopted to replace the quartz substrate and reduce light dissipation..Lasing is observed at a wavelength of 602.2 nm with a narrow linewidth of 0.7 nm and the lasing threshold is low to 6.?J/pulse.The two structures are simple to fabricated,especially the second structure,which has a high Q value and a low pump threshold,and has good research value and application prospect.4.The PLED(polymer light-emitting diode)is designed and fabricated based on MEH-PPV as luminescent material.Quasicrystal structure is added to MEH-PPV layer to localized the light horizontally.Through electrical pumping,the lasing action is observed at A = 607 nm with an FWHM of 0.5 nm,and the threshold current of lasing is 0.8 mA.The turn-on voltage reads 5.5 V.This work provides a new idea for designing the electric pump laser at visible band and lays a foundation for the future development of controllable compact tricolor source.