Limitations of ICCD detectors and optimized 2D phosphor thermometry

Abstract

This paper presents investigations on the limitations of intensified CCD (ICCD) cameras when performing quantitative 2D temperature measurements using thermographic phosphors. The temperature is evaluated using a two-color ratio technique, which demands high signal linearity of the detector. However, this work shows that the ICCD cameras used suffer from nonlinearity at levels of irradiance that do not necessarily produce particularly high count levels, i.e. well below the saturation limit of the A/D converter. For the phosphor thermometry, this results in false absolute temperature readings and decreased measurement precision. The results show that there is a useful workspace in the irradiance/camera gain combination where the detector should preferably be used. A response function for the ICCD camera used is constructed. Furthermore, in order to perform quantitative measurements, there is an upper limit of counts that should not be exceeded. This limit must be investigated for each experimental configuration since it depends on the characteristics of the specific light source and also varies between different cameras.

The saturation of the fluorescence and its consequences for laser-induced fluorescence thermometry in liquid flows

“…They can be a major issue for quantitative measurements based on light intensity (Lindén et al 2012). The camera response to light irradiance was therefore characterized for different amplification gains (i.e., different voltages applied between the input and the output of the MCP).…”

The anomalous sodium doublet D2/D1spectral line intensity ratio – a manifestation of CCD's presaturation effect

“…All measurements described in the present study were performed without applying the microchannel plate (MCP) normally serving to intensify the signals, because the results of some previous studies 26,27 had shown that this part of the device had been responsible for nonlinear response of ICCDs. To avoid confusion, from now on, we shall denote our detection device by CCD (instead of ICCD).…”

Optical Detection Methods for High-Throughput Fluorescent Droplet Microflow Cytometry

“…ICCD sensors have image intensifiers in front of the sensor to boost the number of incoming photons [ 102 ]. This improves sensitivity in low-light scenarios at the cost of a higher supply voltage (1 kV) and reduced dynamic range [ 103 , 104 ]. EMCCD sensors have a similar gain performance to ICCD.…”