Spectroscopic and lasing characterisation of a luminescent phenylene/bipyridine polymer

• Published in: Synthetic metals Vol. 158; no. 19; pp. 758 - 766
• Main Authors: Bansal, A.K., Holzer, W., Penzkofer, A., Hörhold, H.-H., Klemm, E., Frank, W., Kley, E.B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2008; Elsevier
• Subjects: Absorption and fluorescence spectroscopy; Amplified spontaneous emission; Applied sciences; Distributed-feedback lasing; Electrical, magnetic and optical properties; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Laser materials; Low-Q laser oscillation; Optical materials; Optics; Organic polymers; Phenylene/bipyridine luminescent polymer; Physicochemistry of polymers; Physics; Properties and characterization; Travelling-wave lasing; Travelling-wave lasing; Distributed-feedback lasing; Phenylene/bipyridine luminescent polymer; Absorption and fluorescence spectroscopy; Low-Q laser oscillation; Amplified spontaneous emission; Phenylene derivative copolymer; Thin film laser; Transparency; Distributed feedback laser; Pyridine copolymer; Fluorescence; Laser materials; Experimental study; Thin film; Luminescence decay; Organic solution; Conjugated copolymer; Optical properties; Aromatic copolymer; Travelling wave laser; Optical absorption
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2008.04.029

The luminescent polymer, poly[2,2′-bipyridine-5,5′-diyl-(2,5-dihexyl-1,4-phenylene)] (abbreviated PPBpy) dissolved in tetrachloroethane (TCE) and as neat film is characterised by optical absorption and emission spectroscopy. The absorption and stimulated emission cross-section spectra, the fluorescence quantum distributions, fluorescence quantum yields, degrees of fluorescence polarisation, and fluorescence lifetimes are determined. A lasing characterisation is carried out by pumping with single second harmonic pulses of a mode-locked ruby laser (wavelength 347.15 nm, duration 35 ps). The excited-state absorption at the pump-laser wavelength is determined by saturable absorption measurements. Laser oscillation of the polymer in TCE in an uncoated rectangular cell was achieved by transverse pumping using the cell windows for light feedback. From the laser threshold pump pulse energy density the effective stimulated emission cross-section at the lasing wavelength is extracted. The travelling-wave lasing behaviour of the polymer as neat film is studied by analysis of the amplification of the transverse pumped spontaneous emission. Surface emitting distributed-feedback lasing was achieved with a neat film on corrugated second-order periodic gratings.