Excitation Density Dependence of Optical Oxygen Sensing in Poly(9,9-dioctylfluorene) Waveguides Showing Amplified Spontaneous Emission

Abstract

Reversible oxygen induced emission quenching of both the Spontaneous Emission (SE) and the Amplified Spontaneous Emission (ASE) of poly(9,9-dioctylfluorene) waveguides is demonstrated. We show that ASE shows a stronger quenching than SE, up to about 6.2 times, but also a stronger decrease when the excitation density increases. We conclude that the fast increase of the ASE decay rate is the main process in determining the ASE detection sensitivity, limiting the potentiality of sensitivity improvement of ASE with respect to SE.

Air Sensitive Amplified Spontaneous Emission in Lecithin Capped Cspbbr3 Nanocrystals Thin Films

“…The constant RQ ASE above 0.75 mJ cm − 2 suggests that the ratio between the time constant of the air-induced exciton quenching process and the ASE lifetime does not appreciably vary in the investigated excitation densities range. Differently from polymeric samples where the RQ ASE was demonstrated to be strongly dependent on the excitation density [42,51], in our study the ASE quenching results independent of the excitation density, giving the possibility to exploit it for a potential device regardless the pumping conditions, thus clearing the way for possible applications of ASE gas sensing with CsPbBr 3 NCs.…”