Parametric investigations for frequency-domain lifetime PSP technique (FLIM)

Abstract

The effects of measurement parameters on frequency-domain fluorescence lifetime imaging (FLIM) with a new CMOS camera sensor (pco.flim) were investigated. Two lifetime parameters, the demodulation index m and phase angle were used as a function of pressure. Pressure calibration tests were performed with changing measurement parameters, concluding that the increasing excitation modulation frequency gains the pressure sensitivity of lifetime parameters which is normalized by a reference condition (100 kPa, 303 K), shown in figure 1. In contrast, the signal-to-noise ratio (SNR) of lifetime parameters becomes lower with increasing modulation frequency, shown in figure 2. The excitation amplitude and average intensity should be as high as possible to reduce the shot-noise influence. Both modulated excitation, sinusoidal and square, result in the same pressure sensitivity and SNR