Abstract
We demonstrate a fast and cost-effective method of detecting flaws in polymer optical fibers (POFs) using an infrared thermometer. The optical loss dependence of the measured temperature at the flaw is found to be linear with a proportionality constant of approximately 0.74 °C/dB when the propagating light is 24.5 dBm (282 mW) at 1.55 µm. The propagating optical power dependence of the measured temperature at the flaw with a fixed loss also shows a linear behavior, which predicts that a high optical input power is preferable to precise estimation of the loss.