Most commercial polarimeters are not suitable for low repetition frequency light sources, so we employed a rotating quarter-wave plate (QWP) measurement system 31 as our homebuilt polarimeter. This setup includes a rotating QWP and a linear polarizer, as depicted in Fig. (a), to measure the Stokes vector of the output dye laser emission. The discrete intensities of the optical beam measured at different rotating angles of the QWP are given by: