Design of tunable liquid laser based on presence of the conjugated-polymer counter influencing the spectral properties of the oligomer

Abstract

Abstract In this paper, we studied the optical properties, lasing properties, and time-resolved spectroscopy (TRS) dynamics of the energy transfer between the conjugated oligomer (CO) 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF) and conjugated-polymer (CP) influencer poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) in a toluene environment. The oligomer 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF) exhibits single amplified spontaneous emission (ASE) in a solution for a wide variety of concentration and solvent environment, but it produces dual ASE under the influence of MEH-PPV. The dual ASE of the oligomer is due to the interaction between these two laser materials, and it is studied using various spectroscopic techniques. The TRS showed that the presence of the CP in the CO solution does not change the excited state dynamics of the CO, and the fluorescence of the CO is quenched, and the fluorescence of CP is enhanced simultaneously; hence, the underlying mechanism could be modulation of the absorption band at specific wavelength region (460 ± 10 nm). Under an optical cavity (100%–60% reflectivity plane mirrors and with internal grating), a tunable laser with a 6 nm full width at half maximum (FWHM) from 560 nm to 580 nm and attenuation from 600 to 650 nm was observed. Spectrally narrow peaks were obtained at various wavelengths by changing the cavity mirror distance. This strategy of obtaining a laser tunable from 560 to 580 nm, in addition to dual ASE (436 nm and 464 nm), from a CP and CO blend could potentially facilitate the development of an efficient, low-cost laser.