TSR technique can be well used to investigate the response to a short heating pulse in the time domain. As the time, when the heat starts to accumulate above a defect, is characteristic for its depth, this technique is appropriate for creating a 3D map of the sample. A CFRP structure with different number of layers and with Teflon inserts was used to demonstrate this technique. In order to calculate the depth of the artificial delaminations and the thickness of the layers, the starting time of the accumulation is determined for each pixel separately, based on the maximum of the 2nd derivative of the fitted temperature-time function and a 3D map of the structure generated.