Optically Pumped Intensive Light Amplification from a Blue Oligomer.

Aljaafreh Aljaafreh,Prasad Prasad,M. Al-Mogren M. Al-Mogren,Alahmed Alahmed,Alsalhi AlSalhi

doi:10.3390/polym11101534

Abstract

We demonstrated the time-resolved dynamics of laser action from the conductive oligomer (CO) 1,4-Bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF). Absorption and fluorescence spectra were studied for BECV-DHF in different solvents under a wide range of concentrations. The Fourier-transform infrared spectroscopy (FTIR) spectrum was measured using simulation and experiments. The Ultraviolet-Visible (UV-VIS) spectra of the BECV-DHF were simulated in two different solutions. This CO formed a dimer and had two vibration bands in nonpolar solvents, partially dissolved in polar protic solvents, and created an H-type aggregate in polar aprotic solvents. BECV-DHF produced amplified spontaneous emission (ASE) at 464 nm in many solvents. The high efficiency of ASE is due to the waveguiding and self-assembly nature of the oligomer, which is very rare for optically pumped systems. However, BECV-DHF did not produce ASE in polar protic solvents. BECV-DHF produced ASE in both longitudinal and transverse pumping, and the full-width half maximum (FWHM) was 4 nm and 8 nm respectively for different solvents, such as toluene and acetone. The CO had a very low threshold pump energy (~0.5 mJ). The ASE efficiency was approximately 20%. The time-resolved spectroscopy (TRS) studies showed a temporal Gaussian-shaped ASE output from this CO. BECV-DHF shows remarkably high stability compare to the conjugated polymer (CP) PFO-co-pX.

Highlights

A material must possess various unique properties in order to be beneficial as a laser gain medium [1,2]
We showed that a similar that the 9,9-dihexyl-9H-fluorene segment A contributed to the chromophore and that the 9-ethyl-9Hmolecular structured conjugated polymer (CP) PFO had an absorption peak at 360 nm, in which the 9,9-dioctyl-9H-fluorene carbazole segments B have a little influence
5.InConclusions this study, a high-efficient laser material was studied theoretically and experimentally with results that were in agreement with each other

Summary

Introduction

A material must possess various unique properties in order to be beneficial as a laser gain medium [1,2]. At high concentrations, the photoluminescence efficiencies drop for conjugated polymer laser chromophores, despite having the remarkable properties above. Another crucial property of any gain medium is that it must show a large cross-section stimulated emission, which is nominally in the range of σ = 10−15 cm for conjugated polymers [5,6].

Methods

Results

Conclusion