Random Laser Of Polymer Fiber And Its Statistical Study

Since Letokhov theoretically proposed the necessary condition for the formation of random lasers,that is,the gain in the disordered system is greater than the loss,scholars have done a lot of research in the field of random lasers.Random lasers have attracted a lot of attention in the academic world because of their low cost,easy manufacturing,low spatial coherence and small size.Random lasers have been widely studied in stochastic systems doped with laser dyes.In this paper,we introduce the novel N,N’-di-(3-(isobutyl polyhedral oligomeric silsesquioxanes)propyl)perylene diimide(DPP)organi c/inorganic hybrid laser dye,whcih is studied for the properties of the random laser.Meanwhile,the organic/inorganic hybrid laser dyes has been reported as active scattering medium including scatterer and gain medium and is composed of perylene diimide(PDI)as gain media and polyhedral oligomeric silsesquioxanes(POSS)as scattering media.The random laser photostability of the organic/inorganic hybrid matrices is enhanced by incorporating silicon-containing POSS nanoparticles(NPs)into the structure of the organic monomers.In this work,we prove the transition from the incoherent random laser to the coherent random laser in the disorder system doped with the organic/inorganic hybrid laser dye.Meanwhile,we found that the hybrid dye DPP has a long lasing lifetime compared with the traditional laser dyes,which is attributed to that the POSS group can suppress the photo-bleaching effect to extend the working life of laser dyes.Among laser dyes,the use of commercial long-wavelength(≥650 nm)laser dyes has distinct limitation,that their absorption at the standard pump wavelength(532 nm)is relatively weak.In this paper,for the limitation,the PM597/NB-doped polymer fibers to construct F?rster resonance energy transfer(FRET)system is prepared by electrospinning technology and the random laser phenomenon of energy transfer is studied.The F?rster resonance energy transfer system enhances the low absorption rate of the long-wavelength laser dye to the fundamental pump wavelength(532 nm)by the dono r/acceptor dye pair,and successfully achieves the F?rster resonance energy transfer random laser.At the same time,we observed the spin glass phenomenon in random lasers,especially the replica symmetry breaking phenomenon by comparing the disordered system with other systems.In this paper,we report a glass-state behavior in an electrospinning random laser with a complex energy level F?rster resonance energy transfer.Under different energy pumps,a clear transition between phasesclear paramagnetic phase and spin glass are observed in a random laser,that is,the replica symmetry breaking.The findings of RSB in FRET-assisted random laser enriches the physical theories in the research field of the random laser and provides a new statistical analysis meth od towards the laser system with complex energy level,e.g.quantum cascade laser.