Effect of Luminescence Lifetime on the Frequency Response of Fast-Response Pressure-Sensitive Paints

Abstract

A mathematical model on the frequency response of pressure-sensitive paints (PSP) is derived. Frequency response of PSPs is usually dominated by the diffusion timescale of gas permeation into the paint layer. However, recent fast-response PSPs have a very short response time close to 1 μs. This short response time is occasionally equivalent to the emission lifetime of luminophores used as the sensing molecules of PSP. In the model, the unsteady light emission process of the luminophores is taken into account with the gas diffusion in the paint layer. Then the effect of two characteristic timescales, the luminescence lifetime and the diffusion timescale, was evaluated using Bode plot. The result indicates that the luminescence lifetime alters the response dominated by the diffusion when the lifetime is close to the diffusion timescale. The gain and phase difference due to each timescale are linearly decomposed in the Bode plot.