Random Lasing from Weakly Scattering Media: Universality in the Emission Spectra from Pi-Conjugated Polymer Films
| dc.creator | Polson, R. C. | |
| dc.creator | Raikh, M. E. | |
| dc.creator | Vardeny, Z. V. | |
| dc.date | 2001-05-18 | |
| dc.date.accessioned | 2026-07-07T02:41:28Z | |
| dc.date.available | 2026-07-07T02:41:28Z | |
| dc.description | When films of Pi-conjugated polymers are optically excited above a certain threshold intensity, then the emission spectrum acquires a multimode finely structured shape, which depends on the position of the excitation spot. We demonstrate that the power Fourier transform (PFT) of the emission spectrum exhibits a certain peak-like structure, which also depends on the excitation spot. Our intriguing observation is that averaging the individual PFTs does not lead to a structureless curve, but rather yields a series of distinct transform peaks. This suggests universality, namely that the underlying random resonators that are responsible for the laser emission from the pi-conjugated polymer film are almost identical. We argue that the reason for such an universality is the large size of a typical resonator, which we determined from the PFT, as compared to the emission wavelength, lambda. This fact is, in turn, a consequence of the large light mean free path, l* approximately 10 lambda in the polymer film. This contrasts previous observations of random lasing in powders, where l* approx. lambda. We develop a simple theory that explains the presence of peaks in the average PFT and predicts their shape. The results of the theory agree quantitatively with the data. | |
| dc.description | LaTeX, 9 two-column pages, 6 EPS figures included | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0105360 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0105360 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/17753 | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.subject | Disordered Systems and Neural Networks | |
| dc.title | Random Lasing from Weakly Scattering Media: Universality in the Emission Spectra from Pi-Conjugated Polymer Films | |
| dc.type | text |