Lasing and transport properties of poly9,9dioctyl2,7. Excitonexciton annihilation and the production of interchain. Very large optical gain due to the stimulated emission is measured directly by pumpprobe spectroscopy. Many technological applications that have had tremendous impact on our society and lifestyle are exploiting the emission properties of organic species such as conjugated polymers and organic smallmolecule semiconductors. Avariety ofoptoelectronic devices have been demonstrated in which conjugated polymers are used as the active. For laser devices, conjugated polymers work as a novel class of solidstate laser active media with great potential for lasing dynamics and optical amplification due to their broad spectra and high optical gains. The dramatic collapse of the emission linewidth to. Influence of aggregates and solvent aromaticity on the emission of conjugated polymers. This leads to spontaneous emission and stimulated emission.
Herewereportthatpolymers containing cinnamic groups can be deformed and. Amplified spontaneous emission and lasing properties of. Tuning the wavelength of lasing emission in organic semiconducting laser by the. Amplified spontaneous emission and lasing in conducting polymers and fluorescent dyes in opals as photonic crystals. Friend stimulated emission, lasing, and line narrowin g in conjugated polymers, proc. Apr 14, 2005 main figure, emission spectra of polymer 1 structures at different pump energies show a low stimulated emission threshold e th of 40 nj cm2.
Lasing and stimulated emission the discovery of gain narrowing in electroluminescent conjugated polymers has launched a new field of research aiming towards. Main figure, emission spectra of polymer 1 structures at different pump energies show a low stimulated emission threshold e th of 40 nj cm2. We show here that a proper alignment of the molecules in. Current opinion in solid state and materials science vol. Current opinion in solid state and materials science vol 5. Schwartz institute for polymers and organic solids, department of physics, santa barbara, ca 931065090, usa.
A multiscale quantumchemistry and maxwellblochequations approach stefan schumacher and ian galbraith physics department, school of engineering and physical sciences, supa, heriotwatt university, edinburgh eh14 4as, united kingdom. Lasing and stimulated emission in spl piconjugated. Comparing the ultrafast stimulated emission and photoluminescence dynamics of mehppv ignacio b. Ultrafast photophysics and stimulated emission from novel. Lasing from conjugatedpolymer microcavities nature. Anewclassof solidstate laser materials fumitomo hide, mariaa. Stimulated emission, lasing, and line narrowing in conjugated polymers. Near diffractionlimited laser emission from a polymer in a. Study of lasing action based on forster energy transfer in optically. Optical properties and amplified spontaneous emission of. Conjugated polymers are attractive candidates for roomtemperature polariton lasers, due to their high exciton binding energy, very high oscillator strength, easy fabrication, and tunability. Organic semiconductor lasers with twodimensional distributed feedback. Friend stimulated emission, lasing, and line narrowing in conjugated polymers, proc.
The most important optical transition connects the. It is still a big challenge to realize dfb lasing in complex photonic crystals. Recent advances in conjugated polymers for light emitting. The ones marked may be different from the article in the profile. Dynamics of photoexcitation and stimulated optical. Recent studies of lasing and stimulated emission in luminescent. Lasing and stimulated emission in spl piconjugated polymers.
Conjugated polymers that respond to oxidation with increased. Read stimulated emission and lasing in conjugated polymers, polymers for advanced technologies on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Osa lowthreshold polariton lasing in a highly disordered. Tuning the wavelength of lasing emission in organic. Distributed feedback organic lasing in photonic crystals. Organic semiconductor lasers with twodimensional distributed. We report measurements of photoluminescence from films of a soluble phenylenevinylene polymer that has prospective importance as the emissive material in lightemitting diodes.
Stimulated emission and lasing in solid films of conjugated polymers. Stimulated emission and lasing in conjugated polymer. The fundamental process of lasing is the interaction of molecules atoms with an electromagnetic field and the positive feedback in a resonant cavity. Sensitivity gains in chemosensing by lasing action in. Polymers free fulltext narrowband spontaneous emission. Unlike conventional photon lasers, population inversion is not necessary for polariton lasing 7, which can lead to significantly lower thresholds 8. Cheng, and yu zhu department of polymer science, college of polymer science and polymer engineering, the university of akron, 170 university circle, akron, ohio 443253909, united states s supporting information. Conjugated polymers as fluorescencebased chemical sensors reported by jay wackerly november 1, 2004 introduction a chemical sensor is a molecule that interacts with another molecule giving a measurable signal in response. Lowthreshold polariton lasing in a highly disordered. We show unambiguously that there is longlived emission in this material due to excimers and estimate that the quantum yield for excimer formation is as high as 50%. Jaggregation has been shown to be beneficial for light amplification in single crystals of.
Following the discovery1 of electroluminescence in polypphenylenevinylene ppv, considerable effort has been directed towards the realization of optoelectronic devices based on semiconducting. Ultrafast intensitydependent stimulated emission in. Thus, semiconducting luminescent polymers offer promise as novel laser materials withgainlengths in the micrometer or submicrometer regime. The emission spectra of plastic microring and microdisk lasers were measured and analyzed. Near diffractionlimited laser emission from a polymer in. Conjugated polymers are considered attractive as gain. Newly developed highfinesse microcavities are described, for which it is possible to obtain lasing thresholds below the onset of excitonexciton annihilation. Polymers free fulltext gammairradiation effects on. Recent advances in conjugated polymers for light emitting devices. Request pdf on researchgate amplified spontaneous emission from. This demonstration of lasing provides direct support for a model10 in which the main photoexcitation in ppv is an emissive intrachain species, and opens the possibility of electrically driven. Almost at the same time, several other research groups reported stimulated emission from optically pumped. Recent studies of lasing and stimulated emission in luminescent spl pi conjugated polymers performed by our group are presented.
A thin film of thickness 380 nm was pumped with different energies, and the film was kept beyond the focal point of a cylindrical lens to avoid the photoablation process destroying the film. Stacked electrospun polymer nanofiber heterostructures. Effective stimulated emission and excited state absorption cross section spectra. Amplified spontaneous emission in freestanding membranes. This cited by count includes citations to the following articles in scholar. Stimulated emission and lasing in conjugated polymers. Optical properties of cylindrical highq polymer microcavities are discussed. Furthermore, the effect of conjugated polymer structures on the laser. Spie 3145, optical probes of conjugated polymers, 1. In the case of a dye molecule, laser action depends mainly on the three different electronic states s 0, s 1 and t 1. Polymer typical dopants peak conductivity peak emission pa.
Osa enhancement of random lasing based on the composite. Optimizing the excited state processes of conjugated. For laser applications, the polymer as active medium has to be combined with an optical feedback structure that is suitable for electrical carrier injection. Mahrt, current opinion in solid state and materials science 5, 143 2001 picosecond amplified spontaneous emission bursts from a molecularly doped organic semiconductor. Stimulated emission and lasing of randomgrowth oriented zno nanowires j. Semiconducting conjugated polymers as materials for solid. Light amplification and lasing in a metaphenylene vinylene. Due to the inherent nature of high refractive index, the selected nanorods act efficiently as scattering feedback centers, which can promote the formation of closed loop paths of the emission arising from nanospheres.
Altering the emission properties of conjugated polymers. Stimulated emission, lasing, and line narrowing in conjugated. Conjugated polymers as solidstate laser materials sciencedirect. Organicbased distributed feedback lasers by direct. We present timeresolved and timeintegrated measurements of optical gain and its effects in films and microcavities made from polypphenylenevinylene ppv. Photopumped gain narrowing and lasing in undiluted submicron thick polymer films have been demonstrated. Patternable conjugated polymers with latent hydrogen.
Semiconducting conjugated polymers as materials for. Sensitivity gains in chemosensing by lasing action in organic. The oxidized polymers have high fluorescence quantum yields in the solid state, with some having increased photostability. Iodine, bromine, trifluoroacetic acid, propionic acid, sulfonic acids. Stimulated emission, lasing, and line narrowing in. Schwartz department of chemistry and biochemistry, uni. Ase and lasing action have been achieved from conjugated polymers and oligomers in much research work,40,41. Dynamics of photoexcitation and stimulated optical emission in conjugated polymers. Polymers free fulltext gammairradiation effects on the. A key ingredient for any laser is a sufficiently high effective stimulated emission crosssection in the excited state. The mechanism for linenarrowing vinh doan, vu tran, benjamin j. In recent years, conjugated polymers have become an attractive new gain medium for lasers that are tuneable across the visible spectrum. The oxidation is accompanied by spectral changes in the absorption and emission of the polymers, which are dramatic when oxidation causes the copolymer to acquire a donor. For laser applications, the polymer as active medium has to be combined with an optical feedback structure that is.
Narrowband spontaneous emission amplification from a. Excitonexciton annihilation and the production of interchain species in conjugated polymer films. It has also been shown that haggregate arrangements with considerable. Amplified spontaneous emission from photopumped films of a. Optimizing the excited state processes of conjugated polymers. Lasing in general comprises population inversion by spontaneous and stimulated emission and the enhancement of oscillation by resonance. The oxidized polymers have high fluorescence quantum yields. In this paper, we report a method of tuning the wavelength of lasing emission with a lowered. However, to date, polariton lasing has only been reported in one conjugated polymer, laddertype. Optical properties of cylindrical, highq, polymer microcavities are discussed. Lasing and stimulated emission in conjugated polymers. Conducting polymers cps have attracted great interest for their.
Ultrafast intensitydependent stimulated emission in conjugated polymers. Patternable conjugated polymers with latent hydrogenbonding on the main chain kun yang, tianda he, xiaoyi chen, stephen z. Recent studies of lasing and stimulated emission in luminescent pi conjugated polymers performed by our group are presented. The field of conjugated polymers, or conducting polymers, has soared.
Conjugated polymers that respond to oxidation with. The molecular switches are photoresponsive cinnamic acid type molecules such as cinnamic acid ca16 and cinnamylidene acetic acid caa17, which are able to undergo ef. In the case of haggregation, the criteria for such processes are still under debate. Threshold whispering gallery mode lasing from self. The emission spectra of plastic microring and microdisk lasers are measured and analyzed. Considerable research efforts have been devoted to the investigation of distributed feedback dfb organic lasing in photonic crystals in recent decades. A simple and general approach has been developed for the enhancement of random lasing based on the composite consisting of nanospheres and nanorods array. We present stacked organic lasing heterostructures made by different species of lightemitting electrospun fibers, each able to provide optical gain in a specific spectral region.
Aggregation quenching of luminescence in electroluminescent. Advances in conjugated polymer lasers semantic scholar. Dynamics of photoexcitation and stimulated optical emission. Optical properties of cylindrical highq polymer microcavities are. Stimulated emission properties of sterically modified. Index termsmicrocavities, polymer lasers, stimulated emis sion. Lowthreshold, roomtemperature polariton lasing is crucial for future application of polaritonic devices. High photoluminescence efficiencies and large stimulated emission crosssections coupled with wavelength tunability and lowcost manufacturing processes make conjugated polymers ideal laser gain. Recent citations modification of emission wavelength in organic random lasers based on photonic glass yujie chen et alphotoconductivity and photoluminescence. The journal of physical chemistry b 2006, 110 49, 2489724902. We here present various optimization strategies for electrospinning methods which have been implemented and developed by us for the realization of lasing architectures based on polymer nanofibers. In addition, the amplified spontaneous emission ase from mdmoppv and efficient.
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