I have measured an exponential decay which is distorted by detection system. I measured the transfer function of the detection system in frequency domain. I performed convolution between real true exponential and transfer function and fit it with experimental data. I get good agreement for lower time constant but for high time constant, it is not working. What would be the possible regions?
(I only measure the amplitude as a function of frequency for the transfer function. I write a complex function with some parameters and fit it’s absolute value with experimental transfer function to get the complex transfer function back.)
Without access to the actual data it will be quite difficult for anyone to offer a decent response to this question.