The Study Of Organic-molecule Aggregation Laser

Size miniaturization of laser devices is the shape of things to come in laser technology.Organic microlasers have attracted more attention in ultra-sensitive chemistry,bio-sensor and on-chip information processing due to their intrinsic advantages of flexibility and controllable excited-state process.In this paper,based on the concept of"aggregation laser",the performance manipulation and dynamic sensing of organic microlaser were realized by adjusting the way and path of aggregating process.In aggregating process,organic luminescent material used here can shine laser from nonluminescent states.Meanwhile,aggregating process gave rise to immediate formation of high quality resonators.This thesis focused on the realization of aggregation laser,performance optimization and manipulation and sensor application.Detailed research contents and results are as follows:1. A novel organic microlaser,i.e.,aggregation laser was proposed and achieved by several realization methods,including liquid-phase self-assembly,photo-curing and organic molecular self-aggregation.Based on the mechanism of enhanced luminescence caused by molecular motion limitation under van der Waals force,aggregation lasers were realized by liquid-phase self-assembly with tetraphenylethylene-BODIPY?TPE-BODIPY?and benzothiadiazole modified vinyl cyano derivatives?BPMT?molecules.Aggregation lasers with lasing threshold of 0.266 MW cm^-2and quality factor?Q?of 3090 were demonstrated after 7-fold enhanced luminous intensity of TPE-BODIPY molecule and spontaneous formation of polymer microspheres.According to the similar method,based on BPMT molecule,aggregation laser was achieved with the threshold of 17.1 k W cm^-2and Q of 3964.Aggregation in photo-curing process gave rise to laser emission with low threshold(28.8 k W cm^-2)and high Q factor?2327?after 15-fold enhanced intensity of TPE-BODIPY and microcylindrical cavity formation.The self-aggregation lasers were achieved by generation of new excited-state level after luminescent molecules self-aggregating.The highly polarized3-?N,N-diphenylamine?-11-azabenzoanthrone?CNDPA?molecules spontaneously aggregated from the polar solution into polymer microspheres,and the PLQY of CNDPA was rapidly increased from 0.5%to 38%.Aggregation lasers with the threshold of 3.0 k W cm^-2and Q factor of 4268 were demonstrated by optically pumped the CNDPA microspheres.2. High-performance aggregation lasers with high doping concentrations,great photostability and single-mode emission were demonstrated by performance optimizing.By molecular design and aggregation optimization,two kinds of aggregation lasers with high doping concentrations and long operation lifetime were demonstrated.One is the yellow aggregation laser with more than 10 wt%doping concentrations and over 5.4×10⁴pulses output stability.The other is the deep-red aggregation laser with the concentrations of more than 22 wt%and the stability of more than 10⁷pulses.In addition,we developed new methods to prepared single-mode microlasers with high stability and ease of large-scale fabrication.By introducing cavity loss in the aggregating process,single-mode aggregation lasers were demonstrated with low threshold of 2.08 k W cm^-2and high side-mode suppression factor?SMSF?of 20.3 d B.For overcoming the complicated preparation and poor stability of the coupled cavity by micro/nano operation,single-mode aggregation lasers with high stability and SMSF of 22.9 d B were demonstrated by aggregation templates of structural fibers.3. Wavelength-tunable aggregation lasers with emission over 700 nm were demonstrated by aggregating manipulation.The lasing properties of aggregation lasers could be significantly manipulated by introducing other functional guest molecules.Near-infrared aggregation lasers with 760 nm were fabricated,while ICT strength was enhanced by HCl molecule bound onto CNDPA in aggregating process.Wavelength-tunable aggregation laser was realized by stimulated with HCl and NH₃·H₂O and showed good cycling stability.In addition,single-mode tunable aggregation laser with wavelength range from 737.3 nm to739.7 nm was realized by temperature modulation of refractive index of the gain medium.4. The application of aggregation lasers in high-sensitive chemical sensing,temperature and humidity sensing were explored based on the high-sensitivity response characteristics of aggregation microcavities.H₂O₂sensor with a sensitivity of 5.06 wt%nm^-1was demonstrated,while lasing wavelength shifted linearly with the content of H₂O₂.Based on the negative refractive index temperature coefficient of the gain material,temperature sensor with a sensitivity of-0.14 nm K^-1was realized.And humidity sensor with the sensitivity of 37.3 pm?%RH?^-1was fabricated based on the self-assembled hemispherical resonator with BPMT.